Yellowstone Next Week - Freezing Temps Concern

I've spent many days below freezing in my trailer. Sounds like I have a bit more insulation than you have, but I wouldn't worry. The heat from the trailer will keep you from freezing. One piece of advice - have at least half a tank of water in your fresh tank. I have been there when the water spigot froze, and I didn't have enough water in my fresh tank to last the day.