Without spoilers, I would like to know too. I tried limit my rests at first, but gave up on that when stuff got annoyingly difficult.

I'm soon done with the first area and only thing I know so far is that on your second full rest theres a small main plot progression. Other than that no quests seemingly have had time limit so far, I could leave them right before a hard boss battle with civilians in immediate danger and can come back many rests later and nothing has changed.