Wow! I thought we were hardcore, but living in a tipi through a Montana winter?? Especially this one!
My wife and I, and our two young children live in a 16x20 wall tent in the north Georgia (USA) mountains and use a rocket mass heater. First winter we heated with a small iron box stove, and burned a LOT of firewood, like 4.5 cords or so, even in a mild winter. Not what we wanted to be doing. We built the RMH this fall and are burning next to nothing and generating a respectable amount of heat. A lot of my firewood stash is finding new careers in the garden bed retention, fence shoring, and hugelkultur industries. Because we're converting our tent platform to a cabin soon, we haven't added thermal mass to the bench, which could make all the difference, but we have trouble staying warm enough through the night with just the stove. For this one winter we're using a propane space heater to pick up the slack at night and allow us to stay in bed all night, sleeping, and not up tending the fire. In our admittedly limited experience with the RMH it takes too much regular attention to use through the night, and Ianto Evans would probably be quick to point out that that's not the way it's intended to be used anyway. So we use a little gas. Just for a few months until we get that hard structure built. I'm not at all sure the building department is going to understand, so I don't want to have to move that much weight twice. We're two years deep into coppice management and judging by the fuel preferences of our "dragon," (his name is Smaug) this seems like it's going to be a winning combination...once we get some hard walls, insulation, cob and plaster around that stove. The combustion unit weighs about half a ton itself, and holds onto heat really well, but I'm guessing another 2-3 tons of mass bench will be a substantial upgrade for next winter.
But compared to us, you guys definitely got all the stones. Thanks for sharing your story! Best wishes to you. The light and sound of living in canvas is hard to beat. We'll keep our fingers crossed for breaks in the weather out there (aka "May"
My blog address is www.smallbatchgarden.blogspot.com if you'd like to see more pics and read commentary. Oh, and I think the up-thread suggestion of wrapping the second larger tipi around the smaller one is a real winner...