[Creeker]

I would be surprised the tank froze if you had the tank heater on and its working properly. I would be checking individual lines. I'm about an hour from you and can't imagine staying in a camper the last couple days. It was 5 here this morning and it's only in the upper teens right now.

I think skirting would benefit you greatly. Especially with a little heat added underneath.

Good luck getting un-froze and welcome to the forum.