Hi, here's a quick note about heating my cedar-framed foamie TT called the Nutmeg.
It was about 38F yesterday morning, and so I put in a Pelonis Disc Furnace (the very small cube ceramic heater with low temp heating elements). At the lowest setting, it brought the cabin temp up to 74F in less than an hour. At about 3/4 Max, it was about 20 minutes.
I think it can extend the camping season significantly.