Just did this myself, but I augmented our gas furnace, instead of replacing it. The two technologies can work in tandem, if it gets too cold for the heat pump t

Just did this myself, but I augmented our gas furnace, instead of replacing it. The two technologies can work in tandem, if it gets too cold for the heat pump to work efficiently. You do need more room for the heat exchanger. But you can also get “mini split” units which are basically single room units.