Got those and they are indeed nice. Prob'ly just recommend folks make their own tho at the price point.I do have a suggestion for temperature control on those cold winter nights. The main loss of heat comes from the windows on the doors. We have designed an insulated, waterproof, and reflective window cover. It also works great in the summer for keeping the cabin cooler. below are a couple pics. All you need to do is mount a couple magnets on the door and your done. They are $250 shipped for the pair. I'll admit they aren't the cheapest but they are really nice.
And they have nothin' to do with the poor performance of the thermostat. Too hot … then too cold. Still open for suggestions and searchin' for a suitable replacement that can moderate the interior temperature more efficiently and comfortably.