I was looking for a place as far north as I could go. If you like spacious comfortable places with a boat ramp, fully plumbed fish and bait station, water, sewer and electric, check out Fort Daer Landing and Recreation Area Campground in Pembina, ND. Full hookup RV sites are 20/nt, tent sites are 10.
I did 5 days. 4 without a data connection and I'm not complaining.