The difference between 33-35 and 37 is so small I think it is effectively meaningless. There aren't many sites that are so specifically measured that a 33-35 would fit but a 37 wouldn't. If necessary, you park the tow vehicle elsewhere.
30 vs 37 is a more meaningful difference. I needed a bunk house and that pushed us to 35 (mfg measurement, actually measures 37 with the spare tire).
Every time I think our trailer is too big we have bad/cold weather when traveling with others and we all end up coming inside to eat and I'm glad I have the space. We travel with kids which makes a difference.
The tightest camping spot I've been in was an old forest service campground. On the other hand, I've been at other state campgrounds with large sites. Kind of depends on when the campground was built or overhauled.
I find planning ahead works fine. My father in law at 25 ft can go anywhere but it is small enough we all can't eat inside.