I have a non-insulated Pop Up hut and have never had an issue with it being warm in there. Most of the time I don't even need a heater, but when I want to get toasty I crank the heat to low and I am good to go.

I always wanted a flip over because I always end up fishing alone and didn't like setting up the pop up in the wind, but now that I have way more practice setting up on the ice I am fishing in minutes with the pop up and have loads of room in there.

Good luck finding something that works well for you.