I run a "sheepherder" type tin wood stove in a 14" x 16" wall tent when moose hunting. If you are not careful it puts out so much heat that you cannot stand it.

I have used double layer Canadian Forces Artic tents in very cold weather, the double mantle naptha lantern takes the chill off until it was time to sleep. We also run a naptha stove inside to cook but the tent is well vented. The sleeping system is excellent and I always slept well, unless I rolled off the pad onto the tarp over the snow, then it got cold fast.

Mike