Strangely enough it's about 50/50. This fall I'm going to blow in insulation into the voids on the one wall and the one partial wall that isn't insulated, as well as insulate the door. That will help with heating the master bedroom (which has the floor insulated in the spots above the garage) a bit more as well.
Not strange at all- mine is only insulated on the shared wall with the house. I'm starting with blown insulation above the ceiling, since that will have the greatest benefit. My goal is insulation all the way around and OSB panels for mounting tools, etc. (an epoxy floor would be awesome, while I'm dreaming). I'm not happy with how hot/cold it gets in there, particularly since our chest freezer lives in the garage.