I am still waiting for a good solution to the "rest system". This undortunately isn't one of them.
Tying rest to specific place, will only mean that players have to backtrack to rest. Tying long rests to story progression (and that's what OP suggest from what I understand) means that either game will rely on metaknowledge for success (it is after all handcrafted game with no proceducal generation) or will offer resting places generously enough to make the whole system irrelevant in the first place. There is of course Dark Souls system, that works thanks to respawing all enemies between checkpoints - I could see it work for DnD system. Gaining metaknowledge and what spells to prepare would be part of gameplay loop. And while I might be interested in a game like that, I don't think it's a good fit for BG3.
For long rest to work, we would need a systemic risk/reward system - ambushes were a thing in BG1&2, as discussed before it is more of a flavour then actual mechanic. I think one could impliment it well in real rogue-like - with permadeath, ironman, and systemic consequences. In handcrafted, story driven adventure, resting will always be out of place - unless, of course, someone proves me wrong one day.
