I am camping right now, and have already winterized the camper. We are using the shower house in the Kentucky campground, and using an old Thetford Porto-potty from our pop-up days. That way I won't have to winterize again when we get home.
The heated mattresses work well, so I wouldn't worry about insulation under the mattresses. Reflexfix in the bunk Windows may be helpful, but use bunk end covers if you have purchased them. Expect condensation and take some old towels for drying if needed.
While I ordered the factory tank heaters, I don't plan to use except for occasional nights when it drops into the upper '20's.
2014 F150 SCrew 4x4 Max Tow Heavy Duty Payload 3.5 Ecoboost 6.5' bed Ingot Metallic Silver
2015 Rockwood Roo 21SS