Mike,
I don't know if you can even get one anymore but I'll tell you what a 20 year old straight pipe Hawke insert will do. This is the only heat we use.
Different house, different climate. House is twice as big and on the Gulf Coast. It's 2x6 framed with double brick veneer, no windows on the east and west gable ends which are bricked all the way to the roof. It's insulated out the wazoo including all interior walls and sits on a 15" insulated slab with 8" of slab under the sunken living room. The main ceilings are modestly vaulted and it's a fairly open floor plan. It's completely shaded on all quadrants with live oak, red oak, sawtooth oak, water oak, green ash, pecan and red cedar. Zero solar gain for cheapest cooling. The only wall that ever sees the sun is the east wall and that's only after mid-winter when green ash and pecan finally drop leaves. Basically, it's an above ground cave.
This Hawke insert is framed into a 3'x4' hole in a ceiling height, 8' wide brick fireplace with heavy steel plate surrounds. It has a variable speed blower system and will accept 22" wood. I burn only oak with the exception of one large cherry tree I harvested about 8 years ago. It doesn't matter if the wood is seasoned or green. Anything I throw in it burns like a champ and I don't use that much. I can't tell you exactly how much but I can tell you that during a typical serious deep winter cold snap that lasts four days with nights in the teens and days in the 30's, I won't go through a fully loaded 4 ft³ wheelbarrow of wood. It's dirt simple to keep the house very warm. When it's cold I'll feed it maybe four times a day and easily maintain 76° or better. If I'm lazy about loading it completely full on a cold night or go to bed really early, it may go down to 72° by morning at the end of the house furthest away from the stove. As long as the doors are left open, all rooms are nicely heated. The only time I can fully open the intakes and let 'er rip with high blower speed is on beastly cold/windy nights when it feels like the only thing between us and the north pole is a barbed wire fence.
I don't remember what this insert cost but it was fairly pricey back in the day. If you can still find one, it's the heater from hell.