That's one of reasons we looked for and bought a new RV without slides ... so we wouldn't have as many decisions to make. ;)
We use Walmart parking lots now and then ... along with church parking lots, state Ports of Entry parking lots, Cracker Barrel parking lots, special commercial business parking lots (with permission), folks' back yards, county fairgrounds, state fairgrounds, county parks, state parks, federal parks, commercial campgrounds, and federal lands out in the middle of nowhere. Flexibility is the name of the game for us.