We had an trailer with a small slide. Never disconnected the electric. We did however have two 6 volt batteries which would give us adequate power for almost a week without recharging. If you don't have two batteries and have room, you should consider adding an extra battery. We would put the slide out once in a while at a rest stop, but since it was a small shallow slide it didn't open the trailer much. As to overnighting in rest areas, officially IIRC, there are only 6 states that allow it. However all allow you to stop for a few hours and rest. Unofficially some states, that do not allow overnight parking, will not bother you if your do not set up like a camper. Whatever you do, do not put out chairs and barbecue or anything that makes you look like your vacationing at the rest area. And respect the rest area. Be considerate of others and keep it clean. At least that's what we've been told and it makes sense. Otherwise, folks would be camping there for 2 or 3 days while exploring the area.