Overnight parking ordinances in my area are aimed at people in the neighborhoods who use the public streets as free parking facilities for their recreation vehicles. In some areas it is the commercial long haul truckers that they do not want parked overnight or leaving their trailers parked in the area for days at a time. The local officials are seldom concerned about an RVer parked for the night who will be gone in the morning.
There are many small towns that provide places for RVer's to stay overnight. They probably figure that the longer they stay the more money they will spend with local merchants. I have learned of these places through the local chambers of commerce and not the usual RV camping directories and websites.