Just returned from a 1000 mile round trip to visit in-laws in VT.
Being a lazy cheapskate, I planned it out so that we had 2-3 hour hops each day, staying at Cracker Barrels each night. Worked out great for the most part (though after having supper and breakfast at each one, not sure we really saved any money
Spent a few days at the in-laws', plugged into shore power for lights, furnace and whatnot; no issues. But on the way home, we stayed at a Cracker Barrel extra-long, about 18 hours. That's when the trouble started.
Went to leave, and the tow vehicle didn't have enough juice in the battery to even make the starter chatter. Turns out that the battery disconnect switch on the camper didn't "make" when I turned it on, so for that whole 18 hours we were draining the TV battery instead.
Doofus didn't bring jumper cables, so I did a 1/3 mile hike to Lowe's, bought 'em and conned a nice CB customer couple into giving me a jump. Lesson learned.
Parenthetical comment: The last CB we overnighted at, another RV pulled in after closing time, ran their generator for a few hours, and skated before opening time. I wasn't too impressed with that.