Last winter I heated about 2000 sq. feet with my radiant model 82 Hitzer stove. This area included part of the basement, and the entire first floor. I kept the door to the second floor cracked open to maintain about 50 degrees, if you counted this in the heat load then I was heating about 3200 sq. ft. The house was poorly insulated, had a lot of windows, and uninsulated basement walls. The stove was next to the stairwell in the basement and I just let the heat come up the stairs. I burned anywhere from 50 to 100 lbs per day, and had to run the oil boiler on the cold days.
I previously heated the same house with an Estate Heatrola, the stove wasn't very air tight and only had two settings...hot and nuclear fission
. I burned 80-120 lbs per day in that thing, but it really cranked out the heat and didn't require as much assistance from the oil boiler.
My dad heats about 2600 sq. ft with his model 82 Hitzer stove. He has the radiant model also, no blowers or ductwork. His house is 6 inch construction with new windows and foam insulation on the outside of the basement walls. His basement has two stairwells, one is next to the stove, the other is at the opposite end of the basement and works as a cold air return. The basement is usually about 80 degrees, the first floor about 72. The second floor is normally closed off and kept at around 62 by the oil boiler. During mild weather he opens the door to the second floor and heats that as well, which keeps the first floor from getting too warm. Last winter he averaged 50lbs of coal per day from the 1st week of December to the end of March.