p.s. its hard to beat the smell of nice dry alaska yellow cedar in the fur shed

I use a Shenandoah wood(or coal) stove. It has an automatic draft control, throws even heat, and has a long burn time. Riteway, Hitzer & Ashley stoves have similar features.
On a cold day/night, like it or not, you may find your wife spending more time in the fur shed with ya.

both types of gas produce water vapor when they combust so dont do it. wood is the way to go for this i would say.

I use my grandfathers old round oak woodstove. Bought in 1912. I use to heat my house with it, But the wife said it made too much of a mess.lol. It heats a 30x40 2 story garage in about 2 hrs. I like it about 50 to skin and dry furs. I also use a fan to circulate the air. We have gas to heat the house, But ya can't beat wood heat!!!

If you have an outdoor wood boiler you can run a set of lines to your fur sheds. Works great for me and the heat is basically free.

I heat the house , fur shed and all my domestic water with a Central Boiler. I used electric last winter and the wife was always complaining about the bill. For $100 I was able to run the lines off of the boiler and install a small base board heater. I run a small fan to keep the air moving and the shed stays very comftorable.
It is -8 degree,s this morning and my fur shed is at 61 degrees. Gotta love the wood heat !!!

My shed is only 10x10. I get by comfortably with a small electric ceramic heater. It's usually warm enough to sweat in if your working. (without a coat) If the wife and I are rubbibg each other wrong I'll go out there and watch the game on my little TV, to escape the persicution. Yep thats my manland.

Wood and propane.

Kerosene.