Welcome to the site. You are looking at a great product with Escape Trailers.
The vinyl covered insulation is 3/8" thick covering the ceiling and the walls. You can get another layer of insulation installed as an option, something that most folks do, as it helps in both hot and cold climates.
There is no insulation in the floor, unless you opt for the sprayed on insulation underneath. I added 5/8" of cork for insulation and warmth on the tootsies.
The furnace is not real quiet, that is for sure. I too am a light sleeper, but has sorta gotten used to it. We set ours at 8-9°C at night. We too use a small 120V cube heater on the rare occasion we are connected to the grid, and find it way quieter.