Garage here is 1/2 the basement, boiler room and a couple of fin tube radiators from the oil/hotwater furnce, plus heat from the furnace, keeps the space in the 50-60 range, used to stay around 50 before,more so when its 0 degrees F outside. New garage doors, insulated, no more drafts near the 4 car garage.
I have an old Ashley automatic, oval shaped woodstove that can heat the entire space alone, if its 30 degrees out, it can be 80 near the stove in no time, and I'm not talking cranked up either, just a simple fire going, I use fans to circulate the heat out of there to the other half.
Prior to new garage doors, drafty but fresh air was a good thing, I'd have to keep it cranked up to get the entire space near 70, so I settled at 60, which is easy to hold farthest from the stove, don't like it too hot anyway. In those days 4-5 cord would be about what you need in wood, new doors sure made a difference!
Currently, depending on the weather, and this old non air tight stove, produces heat quickly, I adjust my useage as needed.
Benefit is that 1/2 the house above the stove area, has open floor joists, the heat rises and heats the floor, along that with a sunny day, the furnace does not run much as that zone maintains temperature, those rooms are toasty warm from the floor up.
It's a decent size space that keeps my 850 ford tractor warm so I can use it in the snow, and enough room to work on most things I have, + that space in the back sure is nice after hunting or being outside all day, warms you up, dries things off, TV, fridge, stove, soon to be counter, sink and a few cabinets, I'm very fortunate to have the space and be warm, I know the sky garage all so well !