I have a two car garage and during the winter I keep one bay free to park the wife's car inside at night so she doesn't have to clear snow off in the morning. So alot of my tools are on wheels so I wheel them out into that bay when I work on whatever bike is on the lift in the work bay. The garage is insulated but not heated, although I have electric heaters and a propane sunburst heater. Even when it is -40 outside it takes about a half hour to take the chill out of the air and in about 2 hours I can work in there in without a coat. There's enough heat radiating from the attached house that I haven't seen the temperature inside drop to freezing, the only downside is the floor is concrete so your ankles get sore from the cool air at floor level.
But, since I've been retired I am out there pretty much all day year round working on some project that's bike related. So I have all the comforts of home except for running water and a toilet, but I do have fridge, stereo, TV, and a computer with internet.