we have camped all winter and have not used the propane for heating at all. we live in the deep south and have camped mississippi, alabama, flordia and louisiana. there has been some chilly nights and even a few freezing nights and we got by using a black and decker portable (chill buster) electirc heater and a queen size down comforter....pluse lots of   to keep warn.

we find the insulation on the tm outstanding and sufice with just the above heater.