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.
I loved Van Helsing. It was seriously brain dead entertainment but action was great and the effects were good. I loved The Brothers Grimm, that came out the year after, better though. Horror movie, comedy, action. I passed that movie over back then because of the critics, so took a few more years until I actually got to see it.