Glad I never read those posts some decades ago. We lived in MI and loved winter camping. We often camped at Lake Mitchell in Cadillac and Xcountry skied there. From time to time would need to call a tow truck to pull us out. Spent many many weekends camping at the casino near Sault Ste Marie. They would run an extension cord out the mens bathroom window for a AC hookup in well below zero temps. Coldest I remember traveling in was 35 below. We'd spend our short weekends at the Grand Haven SP where the manager would give us the combo to the back way lock and turn on a power pedistal for us.
We would carry what water we needed in milk jugs kept on the shower floor. The water system was winterized with plenty of antifreeze in the blackwater tanezek so the valves wouldn't freeze. Never used the grey water tank. There was a dump station about 10 miles from home open year round where I could dump every month or two. Slid backwards down a half mile icy steep grade near Cross Village one winter. Wouldn't want to do that part again. Would see quite a few camper pulling snowmobile in upper MI and in the UP. FWIW.