Cold Weather Camper Recommendations

Northwood makes really stout trailers. Solid build throughout. However you need the dual pane windows. You also need to check all the exterior protrusions. Some are not as well insulated as one would hope for. It's more than just R value. You can have high R values but have exterior gaps where outside devices are installed. Also not all slide outs are built the same. Lots of heat loss in some. Check how the slide out seals at the bottom by lifting the carpet flap. Sometimes you can see light thru there. R values are important, but worthless if you have air leaks. JMO but with only a 2" wall you're not going to get house style R values.

Open Range also makes what seems to be well insulated trailers.