So, I am in the beginning stages of looking at pop up truck campers, and I see the same things over and over about cold weather camping and the soft sides not being the best thing for that overall. That is the general consensus it seems, and it makes sense. Those that have the pop ups, why not try to add 4 removable "panels" that are hinged or something so when the camper is popped up, you just fold up the panels on all four sides and now you have actual "walls". They could be some kind of honeycomb or insulated panels. Very crude drawing, aft looking forward, below. Make sense? Already thought of?