I live in middle TN and it gets quite hot here in the summer and unit would be kept in the garage. Would a fridge stay cold enough?
How hot does it get in your garage? Where I live, it sizzles May thru Sept. If it's 105 outside, then it's 105 in my garage by 5pm.
Fridges aren't really designed to maintain a ~60-70
o differential, and so a fridge might be running all the time in your garage. This will shorten its life. A chest freezer with a controller would be better but will still be running more often in a hot garage that it's designed for. And do you park your car in your garage? If yes, add ~10
o to the differential.
Energy efficiency and power savings are great but putting a fridge or chest freezer in a hot-summer garage for any meaningful length of time negates both.