So I was curious. If you took the stereotypical party, and sent them on a journey....how far could they go before they would really need to restock on supplies? (assuming no major issues)
So lets take a typical party (5th level):
Fighter (16 str)
Cleric (14 str, 16 wis)
Rogue (10 str)
Wizard (8 str)
So at base, we would have 48 supplies, or 12 days of travel. Now, lets assume the cleric (who is the only character with any real survival, just through wisdom) is going to hunt to recover supply through the trip. We will assume a standard Tier 1 region for this group, so DC 12. Over 12 days, this cleric should on average acquire 7.8 more supply, so another ~2 days of travel. So on average about 14 days.
If we assume a normal travel pace, this means that a journey needs to be:
240 miles - Run out of base supplies, expect to need to do some hunting
336 miles - high chance to run out of supplies
That said, if your party is anything like mine, they often like to push themselves. As 1 fatigue isn't too penalizing, many groups might push 1 more hour. Now statistically at least 1 member will get a fatigue from the forced march, and considering 2 fatigue is much nastier (bigger penalties AND requires a haven), I think most parties would stop there. So at 9 hours a day, our new numbers:
270 miles - Base supplies run out
378 miles - high chance to run out.
Enter - The Ranger
So lets trade out our rogue for a ranger. This ranger is not super built for journeys, but they are no slouch. Lets assume a Survival check of +5 (+3 prof, +2 wis). Lets give them the Expert Forager knack, and assume a 16 strength.
So the trick here is, our Ranger provides us a minimum of 3 supply every day from grubs, basically guaranteed supply (I think you can actually get 3 supply per short rest but I'm not quite sure there). Further, from their hunting (and ranger's generate double supply), we get 1.5 supply on average. So unless the Ranger is very very very unlucky, they not only will provide the group all the supplies they need, but will actually increase the party's supplies over time. Therefore, unless there are hazards that remove supply, this party with a ranger doesn't really need to worry about supply and can effectively travel any distance in this kind of region.
aka Distance = Infinity
But, if the Ranger just completely flops there rolls and gets no supplies, you are looking at about 50 days of travel (50 base supply, only consuming 1 a day). So our new distances there:
1,200 miles - base supplies run out
1,350 miles - assuming 1 hour of forced march a day.
So if your planning a trip for your party, and not planning to do many journey encounters, these numbers should give you a ballpark of what kind of distance you would need before supplies become a "factor" in your exploration pillar.
So lets take a typical party (5th level):
Fighter (16 str)
Cleric (14 str, 16 wis)
Rogue (10 str)
Wizard (8 str)
So at base, we would have 48 supplies, or 12 days of travel. Now, lets assume the cleric (who is the only character with any real survival, just through wisdom) is going to hunt to recover supply through the trip. We will assume a standard Tier 1 region for this group, so DC 12. Over 12 days, this cleric should on average acquire 7.8 more supply, so another ~2 days of travel. So on average about 14 days.
If we assume a normal travel pace, this means that a journey needs to be:
240 miles - Run out of base supplies, expect to need to do some hunting
336 miles - high chance to run out of supplies
That said, if your party is anything like mine, they often like to push themselves. As 1 fatigue isn't too penalizing, many groups might push 1 more hour. Now statistically at least 1 member will get a fatigue from the forced march, and considering 2 fatigue is much nastier (bigger penalties AND requires a haven), I think most parties would stop there. So at 9 hours a day, our new numbers:
270 miles - Base supplies run out
378 miles - high chance to run out.
Enter - The Ranger
So lets trade out our rogue for a ranger. This ranger is not super built for journeys, but they are no slouch. Lets assume a Survival check of +5 (+3 prof, +2 wis). Lets give them the Expert Forager knack, and assume a 16 strength.
So the trick here is, our Ranger provides us a minimum of 3 supply every day from grubs, basically guaranteed supply (I think you can actually get 3 supply per short rest but I'm not quite sure there). Further, from their hunting (and ranger's generate double supply), we get 1.5 supply on average. So unless the Ranger is very very very unlucky, they not only will provide the group all the supplies they need, but will actually increase the party's supplies over time. Therefore, unless there are hazards that remove supply, this party with a ranger doesn't really need to worry about supply and can effectively travel any distance in this kind of region.
aka Distance = Infinity
But, if the Ranger just completely flops there rolls and gets no supplies, you are looking at about 50 days of travel (50 base supply, only consuming 1 a day). So our new distances there:
1,200 miles - base supplies run out
1,350 miles - assuming 1 hour of forced march a day.
So if your planning a trip for your party, and not planning to do many journey encounters, these numbers should give you a ballpark of what kind of distance you would need before supplies become a "factor" in your exploration pillar.