Prior to starting the rebuild of the Fallen Hero's Dream Ride I spent a few days drywalling and insulating my 2 car garage. I used batt insulation in the walls and blew in cellulose in the attic. Installed a garage door insulation kit. I use a portable 110v oil filled heater and keep it at 50 degrees (had many days in the single digits/teens). I should have done it 15 years ago.