Idk anything about any other campers than arctic Fox.
Had an 05 that we used down into the teens? Maybe colder at night for a few nights.
Heater ran dang near constant. There's a few things you can do to help insulation wise.
Our 03 now would be worse I think, built a little different.
For 1 person you could function no problem with the slide in. Just have to go sideways out the door.
I like the big tanks and double 30lb propane (in winter). For winter camping longer than weekend trips I'd want to do some work to economize on the heat bill. Also wouldn't do it without a generator or plug in. Little Honda could do everything including heat up the truck. I'd run the Honda for a couple hours on the block heater in AK when it was -20 out snowmachining and I had a couple bad injectors. But any good running newer diesel, save for the Pstokes up thru the 6.4 aren't very cold blooded. In good shape they'll start down at -25 pretty easy. But I wouldn't camp in those temps anyway.
