Not to steal the thread started by Peter about heating his garage during the holidays, struck a note in my brain about when I was building my house in Alabama. So here we go........
When I built my house in Alabama? I insulated EVERYTHING, including interior walls, garage, and garage door. In January, I could heat my 20' by 20' garage, errrrrrr, shop with a single small ceramic heater plugged in 1 hour before going out in the "shop". It was great..!!!! I just don't see why folks don't treat the garage when constructing as part of the house living spaces. Cost me $75 more for insulation and an additional $600 for the double-walled, insulated steel garage door. Yea...It was a total of $675 more for construction costs of the house, but that was nothing for gaining the overall benefit over the years.
At least I did one "good" thing in my life time. Sure wish I had that garage here in Arkysaw......