My wife loves electric blankets - we use one in the house all winter. Before our TC, we camped at electric sites so she could have her blanket in the tent.
On shore power, it translates well to the TC. I set the thermostat to 55 or 60 and we're toasty under the blanket. If the temps really drop, the furnace will kick on. If not, we're not heating the whole camper and burning propane.
If we were going to dry camp in the cold, I'd do sleeping bags, down comforters, etc. It's much easier keeping the humans warm than the whole camper.
Our furnace does seem to cycle between "too hot" and "too cold" also. It's a small volume to heat and a cheap thermostat. In the mild temps we camp in, I think the duty cycle of the furnace is just too short - a smaller furnace running a longer cycle would provide more even heat, and less "overshoot" of the set temp.