That [8hr short rest / 7day long rest] sounds quite extreme, but if you've thought about the pacing of the adventure, and can make it work, sure why not. Personally I run all my games now with a simple variant from the DMG, where you just don't recover any hp from an overnight rest, so you have to use spells and hit dice before going to sleep; that doesn't slow the game much at all, but at least makes resource management a little more relevant and means PC's can't always steam-roll the adventure on a completely relentless and unrealistic schedule. I'd just wonder that if you slow the game down to a weekly cycle, how do you deal with what everyone does on their weeks off - not just the PC's, but all the NPC's - as written, the adventure is pretty static, and you have to start making up a lot of "what's next" - if you slow it down from days into weeks, then you've got a lot more work to do, or it all become static again i.e. NPC's all just sit around waiting for the PC's to be ready again...
Well, I've always enjoyed coming up with the narrative for the background elements like that, so it doesn't feel like a hardship to me. Most NPCs have their respective career-responsibilities or associated sycophants to keep them occupied while the heroes are elsewhere, so all I really should need to do is carefully watch the time-pressure on the various NPC storylines* and cut way back on the "XP filler" combat encounters, since I'm not using XP at all for this campaign.
* Most notably Mad Mary, who is written to be pushing the heroes to get killed for breaking into Strahd's home before they've even met the main plot of the book! Thus I won't have Gertruda's abduction occur until I feel ready for the heroes to enter the castle without the protection of Strahd's declared hospitality, and therefore Mad Mary will live in whichever settlement the heroes next visit at that point in the campaign.
And while I am questioning for myself whether a 7-day Long Rest is a better option than the 3-day variant I've read that another DM (I don't recall who) used in their own game, I am certain that I want a Short Rest to be an 8hr sleep, so that the heroes learn early on that avoiding the "wandering monsters" is always the smarter tactical decision, except when they actively want to capture a particular monster for interrogation purposes. It's a genre consideration for me, just like handing out Inspiration like candy for players who volunteer for their characters to become Frightened in the interests of forwarding the horror of the game's story (per "Genre Emulation" on DMG page 241).
That's the other thing I really like about Milestone Rewards; having minor rewards that give instant replenishment of a measure of the party's resources when they advance the story. Keeps the players on-genre, as well as on-mission.
I did give serious consideration to DEFCON 1's notion of starting my campaign with Krezk and the Winery, thereby bypassing the village of Barovia pretty much entirely. But given that neither I nor half my players have ever played this edition of D&D (and the druid's player has never tried any version of D&D before), I chose to ease into this edition with the lower-level venue of Barovia village.
I shall start the heroes at L2 (so that only Cantrips and L1 spells need consideration), and my prologue will have zero combat encounters from the moment the curtain rises until after the heroes are already inside the Death House. The way I see it, my version of Strahd takes the time to introduce himself to these new visitors in his realm, and to invite them to a dinner in their honor at his home, so he definitely wants their capabilities tested out under controlled circumstances. And therefore his various servants (of every variety) will find that his wrath burns like hot coals under their feet if they get too close to the delicious morsels in question.
I am also severely cutting back on the combat inside the house, with the animated armor relocated down to the previous floor, and only animating if heroes try coming down the stairs from room 11 back to room 6. And freezing in place again if they return to the third floor landing, making it an area denial threat, rather than a "wandering damage" provider. Similarly, the animated broom in room 14 gets turned into a jump scare, making a single attack roll with the likely benefit of surprise, then falling to the ground inert, leaving the players to wonder if it was even a monster or just a borrowed bit of game mechanics modeling their characters' imaginations running away with them.
The specter of the nursemaid I plan to be fully vulnerable to the heroes' silvered weapons (as I'm using a variation of the werewolf-hunters hook with a LG community outfitting them with abundant resources before they set out on their quest), and the various combat encounters in the dungeon level I also plan to severely cut back on. The centipedes and grick and mimic are tossed out completely, while the four ghouls in room 29 become skeletons, and the two ghasts at 34 become ghouls. Then I add back in a few swarms of rats that bubbles up from the well in 25 if any of the treasure chests are opened, so that clever players can run back to fetch one to use as a sacrifice if they so desire.
I should point out that I use a different interpretation of Turn Undead, which drives the undead monster in question back to its grave (or other "home" location), rather than simply whatever geometrical direction is 180 degrees away from the holy symbol in question. Which means that having a Cleric on hand is far from a sure counter to undead, especially when you're standing between it and its grave. And of course, the whole domain of Barovia is Strahd's prison, so he's completely immune to Turn Undead, except when delivered via the Holy Symbol of Ravenkind.
That leaves only the insanity of putting 2nd level heroes up against a CR 5 brute with resistance/immunity to the full trifecta of fire/ice/lightning and no weaknesses that can be exploited. Which I estimate as a 75% likelihood of a TPK. Honestly, I'm not sure what I can do to make the shambling mound less-inappropriate a threat; whether it's a matter of dropping all its resistances, halving its HP or damage output, or what else might be viable. I welcome any advice on that point.
After Death House is resolved, that leaves just the potential combat encounters of Morgantha (who could easily be decided not to take any children while the heroes are watching just yet), random murder-hoboing of rats or zombies, Doru in the undercroft (who's been starving for months, and would reasonably be very low on HP as a result), and whatever Strahd the First And Only chooses to bring to Kolyan Indirovich's funeral.
Since I don't expect these players to be eager for random murder-hoboing (particularly when they know there's 0 XP to be earned by doing it in my game) to deplete their strength beforehand, it should be pretty simple for a foursome of L3 heroes to overpower one starving vampire spawn without taking any casualties. Then the funeral itself becomes strictly a social encounter to show that Strahd the First And Only and Strahd XI have very different personas, with Strahd acknowledging that the due to the dead is worthy of giving Ireena time to mourn her father. After which time, she WILL be his.
And that evening (when some of the heroes are likely running on fumes), the black coach arrives to bring the heroes to their dinner party at the castle, at which Strahd XI tactfully answers questions about the "other" Strahd, and gives the heroes their first quest (for him), where I take the C3 tactical encounter map from Expedition to Castle Ravenloft, and place a mad druid who's convinced himself that he's lord of all wolves. And he emphasizes that they should take their own time to recover their strength before setting out, with a Vistana guide and some riding horses that he shall provide for them.
Because this way he can always use Scrying focused on the horses to keep track of their movements across his domain.
Meanwhile, back in the village, Ismark is attempting to step into his father's mantle as Burgomaster and pull the community back together, which will involve the heroes leading the effort to clear the zombies out from some of the village's houses (which I'm interpreting as the fallout from a TPK of the previous group of adventurers lured into Barovia, per EtCR's "Undead Legions" secondary goal) so that those villagers who've fled the recent badness can have a reason to return to their homes. And afterward, I plan Ismark to stay for the rebuilding of Barovia Village while the heroes, who've already proved their valor several times over by that point, take Ireena to the hope of safety in Vallaki or Krezk.
That's what I have in mind for the Barovia Village chapter of my campaign, with Morgantha's kidnapping antics only coming up either at the tail end, or perhaps when the heroes return later to see how the village is recovering with the bulk of Strahd's attentions directed elsewhere.
So, what do you all think of my plan?