Big time and I'm sure it is not anywhere as nasty here in Northern Virginia as it is where you are.
A couple years ago I bought one of these commercial restaurant open patio heaters from Fostoria http://www.infraredheaters.com/och.htm.
I'd seen them used in Germany to heat outdoor patios in ski resorts.
At 8' high it heats a 10' x 12' area and there is one 120Volt model. It can be freezing in the garage but its always toasty in the footprint of the heater. I just move it around the garage depending on what part of the car I'm working on. Nice thing is that it heats the car, the floor, tools in the foot print and me. And it only cost around $150.