Well, no, not literally in a couple of senses. Firstly, had winter actually persisted from 1 winter season through spring, summer, fall, and then the next winter, that's not two years, although it would be more than one, so literally not two years.
Secondly, the "Year without Summer" wasn't a yearlong (or 1 1/4 year long) winter, it was a year that had a late spring, a much cooler than average summer, and an early fall and winter season. This caused many crops to fail and massive famine and disruption even though a total crop failure did not occur. Had there been literally a year-long (or 1 and 1/4 year long) winter, the devastation and death would have been near extinction level for most of the Northern Hemisphere. So, not literally winter for even one year, much less two.
Well the basic premise also includes some light during the day, just not bright sunshine. It has not been pitch black for the past two years. In any case, it's a couple of lines and not something I would judge an entire mod on.
It's actually very few light. 20 hours of pitch black, 4 hours of twilight, in non-blizzard conditions, for "more than two years". No region of Earth can be compared to such a situation for inspiration of what would happen before taking magic into account. The severity of the consequences should also be envisioned by comparing to the earlier "normal" conditions. The average temperature is said to be -45°C during this period. That's mid-Antarctica level, but it also fell upon an area where the average climate is much warmer. I envisioned Icewind Dale as Scandinavia, where summer can be quite hot. The
forgotten realms wiki gives a normal average temperature range was -10 to +21°C in summer, -40°C being described as the low point of the "unforgiving winter". Basically, their yearly average became lower than their usual coldest winter month.
The "Year without summer" mentionned upthread was a temperature anomaly of around 3°C at worst, while we are speaking of a 50°C summer temperature anomaly. The two phenomena have very little in common, as Ovinomancer pointed out, not only in length but also in scope. It was just a rainy, cloudy summer.
While it's just a couple of line, it's exactly for this reason it's easy to correct (maybe an Alexandrian take on this module will include some of them). The most obvious is two shorten the time. RPG often have an odd description of time length, with cities having tens of millenia of history, something I never understood (a gap of a few years is enough for a gaming group to insert adventure in a timeline...) so the easiest fix is to make winter two month late, not two years... It would explain the lack of social change (and lack of mass emigration or even notice of the fact that the situaiton that should probably be widely known to be localized in the Dale since there are many spellcasters in the area and their first instinct when seeing that the day/night pattern is disturbed should be "wtf..." then casting a Sending to inquire if it is the same in Luskan... after 2 month, maybe the information didn't circulate enough). But it would make the human sacrifice very quick to appear. It's not something that could be easily corrected as well. Make sacrifice to Auril a regular occurrence during harsh winters, with sacrifice of food being common, ritual sacrifice of warmth being performed sometimes, cattle sacrifice to be ordered in case of emergency and human sacrifice to be a known occurence in the past but something not practiced for decades...) In that case the ten town just agreed, when realizing, through the illumination problem, that it's not a normal winter, to turn a blind eye to the town who would want to reinstate it. It would explain why such an extreme solution was devised in a rather short timeframe, explain why the people are doing it despite the sacrifice not bringing any visible improvement to the town doing them (they just hope it will stop the unnatural phenomenon, and it's too early to tell). AFAIK, nothing breaks if there isn't a long string of sacrifices but just a handful of them.
With regard to the mood of the population, I wonder what would be the effect. At some point, as other have already pointed out, we get the feeling that it's "business as usual". In Bryn Shander, the local goodwill and sense of humor is dampened by the reduction of the number of visitors and the lack of trade income it brings... Their sense of humor should be dampened by their inevitable death by famine which should have wiped most of their population already instead. And I am not sure a community that turned to sacrificing its own members to survive would be high on the list of places where goodwill toward strangers is a staple. I mean, visitors would be IDEAL sacrifice candidates, unless they are heavily armed PCs... Business as usual is more credible if it's only a delayed spring, not an endless winter (but I can see an endless winter being more dramatic... but I don't think people would "get used to the idea of their impeding starvation"? It's not just like living in Alaska, where you know that you'll survive even if there is a bad winter... it's like being in your house in the middle of the forest fire, hoping the rain will stop the flames before they reach your house, from which there is no safe escape route). As a side note, given Bryn Shander's population of 1,200 and the map in the game which has a walled area of roughly 65 ha, the city's density is fairly low - I was surprised by the large number of housing on that map). It's very easy to depict starvation and insert the story of an exodus attempt that failed ("several families tried to leave by boat, but it capsized when an iceberg rose under it, none survived... that's when we decided to resort to sacrifices like our grand-grand-grandfathers did").
Using magic as a way of sustaining people is also an explanation that works well, of course, but it has limits over a two year period. First, by RAW, the statistics of 1 spellcaster in 100 spellcaster explicitely refer to Monster Manual druid, priest and mage, not the adventuring classes. So, they can't cast useful spells like Goodberries and Create food and water. This is however a very restrictive reading of the situation and not something players should notice as a deal breaker. Even if, usually, they don't get these spells, given Auril's active intervention, it's not a stretch to imagine Amaunator would grant Create Food and Water to its priests. But such a behaviour would certainly turn people toward him more than toward Auril... On the other hand, it's possible to make a plot point out of it to increase the feeling of desesperation. Yes, the winter was terribly harsh and we usually just have enough food to manage, but this year the last harvest was already very poor so we tasked our spellcasters to find a solution... Unfortunately, they can't do it reliably and in the long term. First, doubling the production of crop is bound to fail as nothing grows without light, so doubling 0 is still 0. Goodberries and Create Food and Water are a possibilty for the 12 spellcasters in Bryn Shander, who can pool their resources to feed the population: 30 people for each priest and 70 people for each druid. Assuming an even distribution of spellcasters, that's 330 person that can be fed out of magic in Bryn Shander. It's not enough (and they couldn't have stockiled it as the food created by both spells magically wastes away after a day) to sustain the city... and also, it's mobilizing their entire spellcasting capacity. So, for example, they have the need to arbitrate between producing food and provide healing in case of injuries (which must be a common occurrence when hunting ferocious beasts and fishing with the risk of being immerged in glacial waters). That would bolster the horror feeling of the story. Of course, spellcasting PCs would... either start mass casting food-producing spells for money (you
can make a killing in that case, though it won't make you popular) or, if they are even remotely good... will they really memorize adventuring spells when they know that casting of Bestow Curse at an opponent during a fight will mean they will deprive 15 Bryn Shander's childrens of food for the day?
The problem is also in the uneven distribution of spellcasters. What if the only person in a 100 inhabitants hamlet is a worshipper of Auril or an evil god, or simply uninterested in helping (and just saying "no can do" while sustaining only himself)? Tension could be added to the situations in some settlements.
Magical food wouldn't explain the abundance of predators encountered. If it's not really credible they would survive after more than two years, as the grazers would have disappeared already, they are more of a menace if the timeline is shortened. They ate most weakened preys already (and paradoxically, a very bad autumn and an harsher winter would have weakened most grazers, enough for the predators to enjoy easy to catch preys, until they wiped them all, and now, they are turning increasingly closer to civilization. Especially as the town are doing sacrifice of food by letting it in the open to feed creature Auril is fond of... Increased menace of predator is good in the atmosphere the adventure is trying to convey. Especially as magical healing is lacking as the local druid is producing goodberries
en masse so encounter with a pack of wolves while hunting one of the few remaining wild moose could prove fatal.
It's not that Rime is a bad adventure, it's just that some design choices were made that deprives from the horror mood instead of reinforcing it. Nothing unsurmontable but still. I'll probably wait for an Alexandrian version of it if he gives Rime the same treatment he did for DiA.
