We camped out for three days last February at the State Park for a Valentines dinner and a couple of snow shoe hikes.
It was in the low 30’s to high 20’s at night and we use an electric space heater to keep the TT warm. Warm of course is relative but when we got up it was between 45 and 55 degrees depending on the outside temp.
Once we were out of bed, the propane furnace brought the TT temp into the 60's in a few minutes.
We were a few campsites from the heated wash house so we did not need the water for the bathroom facilities. A five gallon water jug served us for cooking and coffee.
The high temps were in the 30’s but it was very sunny and the trailer stayed in the mid to upper 50’s during the day with only the electric heater. Since we were out of doors most of the time, a 55 degree trailer was just fine.
After dinner and before bed time we ran the propane furnace, as the TT cooled down rapidly once the sun went down. At bed time it was the electric heater only; and a down comforter of course.
I will point out two things; we are canoe campers so waking to cool temperatures is not unusual, and this was a shakedown trip for the TT, to make sure everything but the water was working. We left for a month down south a week later.
