That's the reason for having a small FGRV. They are small and cute. You can squeeze them in almost anywhere. At rest stops, Ill try to find another camper/trailer taking up just part of a truck space and just pull in behind so as not to fill up a space that a truck could use.
Other places I camp are at all-night restaurants, closed gas stations, gravel pits, wide spots in the road, etc. The only time I was asked to move out was at a city park in Wisconsin. Another camper there told the police that he had been drinking, so didn't think he should leave until about 6am. He was allowed to stay.
Once we stayed on business at a fancy hotel on the beach in SanDiego. There were more than several "art deco" busses parked in the best places along the beach parking. I had a friendly visit with one of the owners and it seemed like they spent much of the winter there. There were no-parking signs from 2am to 6am, so they would all leave for an all-night coffee house, then arrive promptly at 6am to take up their residence again. Very law abiding citizens, at least on that issue, I must say!
I just have never worried about that kind of thing. But I know some who have strong opinions otherwise. I'll listen, never argue, then just do my own thing.