I wonder if Zodi has a bigger model.
Sry Gerritt, I can contribute something. I've used the BlackCat in early May in Algonquin. With the ventilation offered in a modern tent with top mesh panel and full fly, the heater made a slight difference in the inside temp, say from 0C to maybe 5 degrees. I don't think that it actually drove off the damp, since the 'burning' of fuel makes a fair bit of water. I could tell you how much water, but I can't really be bothered to do all that figgerin. Then again, maybe modern tents are only supposed to keep you dry, keeping warm is up to you.
I think the same unit with a fan, the Power Cat is a better idea. I thought that most of the heat went directly up thru the tent vent, and a fan to move the air around is a good idea. I expect that would be the same for an ice hut.
If you are really serious about being toasty, go for the Zodi. If you would only learn how to dress for the weather, then the PowerCat would be my choice.