I agree and don't. Mostly agree. Auntie Ethel fight is really hard without a long rest. Tried it. It sucks.
However, the concept you have proposed makes sense. You shouldn't be able to trigger this type of event, rest 8 hours, come back at your leisure, etc. I'd rather get more options than be forced to long rest before every boss. SO anti-climactic.
My issue with resting, besides this, is it is tied to dialogue. So if I don't long rest frequently I miss character development. I also don't like when characters tell me they are tired when they have hardly done anything. We ran through town for 5 minutes. Guess we need to call it a day. All because someone wants to say something to me. That's dumb. I feel like I'm punished for playing smart and not resting a ton.
I also think that there needs to be overarching consequences. If you long rest, thus ending the day, too many times, the gobbos raid the grove and kill the tieflings, or the druids do and seal off the grove just before the gobbos arrive. This would not result in game over. It would just mean bye bye grove.
Also, there should be tadpole side effects to resting too much. The more you rest, THAT is what triggers thr dream guy/girl faster, and if you use Illithid powers, even faster.
This would REALLY cut down on players resting after every battle I would think.
Also, food is dumb. Should be a requirement to resting HP recovery, not used in battle. Who eats ribs in combat, let alone as a bonus action? This would also make resting more limited and food more important.
So in regard to the Auntie Ethel fight difficulty, one of the reasons I said Aunite Ethel "sent [Mayrina] away" instead of "killed her" is to make the story aspect less punitive, in case the player is unable to accomplish the whole adventure in one go. The time aspect should be used to add unique or positive story elements, without the player feeling like they HAVE to always accomplish the mission without taking a rest. There is some benefit if you do, but it doesn't change the overall course of your game. In this case, failing to rescue Mayrina in time might mean that you have the ability to save her later when encountering the Hag's coven, but perhaps now you'll be forced to also fight her newly born daughter, who has already been turned into a hag.
Major or extra powerful items should remain dependent on completing any version of the task, rather than completing the task "perfectly." The reward for completing the event in time could be minor items/inspiration, but most important is the story element making you feel like you accomplished something by deciding not to rest to full after each and every fight.
*Strategy Spoilers*
The Auntie Ethel encounter, fought my first time in one go, was certainly difficult because I didn't know what I was facing, and I kinda just walked into each part of the encounter. However, if you approach the encounter intelligently, it's actual not difficult to do it in one go. First, make sure you have defeated the redcaps before triggering the event, and are fully rested before entering the cottage. Then you trigger the event. Then you can sneak past the mind controlled servants, and break the door to her cellar below (sneak to it or while invisible) to activate her portal leading to outside the cottage. The rest of your party comes in through the portal and can pretty much defeat her in one turn with surprise.
This is the most extreme case, and it's very unlikely you'll figure out every one of those steps on your first run, but the degree of difficulty for the encounter is really determined by how much strategy you use. Making the event time sensitive is not the same as forcing characters to slog through each potential fight on their face. In fact very much the opposite, people have little reason to avoid face-pulling each encounter in the current setup, because there is no consequence to barely surviving a fight, whereas time sensitive events would incentivize you (not mandate you) to approach things strategically to avoid needlessly raising the difficulty.
The overarching story consequences you mentioned, while logical, would be more controversial, because they really would function as a hard cap on long rest use. If you have, say, 6 long rests before the druids close off the grove, then that means you need to focus on resolving that story first, in under 6 rests. If you play the game in a different order, then it will have a major impact on your game trajectory, in a punitive way.
And given how early we are in the story, I don't think it's fair for us to assume that what happens in the grove won't have a ripple effect on how the rest of our story plays out down the line. Each character we meet may show up in the future (or not be there), possibly helping us, inhibiting us, or connecting us to other important people. Those story consequences, and their impact on future story options/magic item availability are too forceful to still say players have meaningful choice. Not to mention there are a number of magic items we would lose access to as a result of this outcome already. When the choice is between "beneficial outcome" and "punishment", there really isn't a choice at all, it's a new story requirement.
That being said, I agree it would be good for Larian to reduce the importance of going to camp for companion dialogue, perhaps by allowing a larger portion of conversations to be had during the day, and only the most important/specific conversations requiring going to camp.
