Welcome rapidir, glad to have you aboard. I would have one question for you. Do you work outside of youre home, or are you at home all day during the winter? If you are home I do not see any reason why the Rocket Mass Heater would not heat your home as well or better than your current wood stove, and use a lot less wood. The reason I asked that question is that the RMH has a relatively small fire box, it is designed to be fired for a short period and then radiate heat from the earthen mass for some hours. Because of your very cold temps I would be worried that if you were not around to fire it on occation during the day your house could get cold befor you returned because of the -50 temps. I am sure that your current stove has a Large fire box that holds a lot of wood and burns for an extended period. Even though the RMH is way more efficient in its burn and the heat that it retains in your home, if your house is not that well insulated it could cool down if you are not there to fire it when ever its needed. My guess is that your home all day during the winter, and that your home is pretty well insulated, you do live in Alaska after all,
My next door neighbor lived in Alaska for some time, he was dean of students at Alaska University back in the 1970's. He has told me a little bit about life up your way in the winter and how you have to perpair. That perperation can be the difference between life and death up there. I do not know if you are thinking about building a RMH this year or next year, it won't be long befor the cold really starts to set in up your way. Good Luck.
PS Matt is our resident expert on the Rocket Mass Stoves, I am sure he will be able to give you a lot more information. He did change over fron a regular air tight metal wood stove for heat to a RMH. He loves it and says he is warmer in the mornings and is burning a lot less wood. You can read about his install here and watch some videos that he has made. I really do feel the RMH is the way to go, just figure in the small fire box into your calculations.
Never doubt that a small group of dedicated people can change the world, indeed it is the only thing that ever has.