Not a car question but I trust you guys

Often the fridge in the garage is the old/inefficient/on its last legs one, could use LOTS of electricity.

@Whitey I agree. The one in question I measured was a 1992 Maytag, which was fairly efficient to start with. It consumes half of the 556 kwh stated for kitchen use when sitting in the basement where it gets opened once a day.A previous one was a manual defrost 17 cu. ft. which used only 350 KWH per year sitting in the basement.

Your worst nightmare would be an early 70s side by side which, when new took 2500 kwh and when parked outside in Houston would consume probably 3500 or so.

The Sears catalogue used to publish the energy consumption of fridges in their appliance section. That info was very revealing. You can also get it from old back issues of Consumer reports.

You could hit the middle ground, use a higher temp when not in use. That should save electric cost. at our cabins no fridge over winter and on and off with a broom holding the doors open between visits. The last fridge from the 50’s replaced 4 years ago, due to bad door seals and a mother that did not enjoy classics, There was no defrost and I think it may have been extremely economical to run.

If a fridge is empty, it uses more electricity than a full one. Pointless to leave an empty fridge plugged in. If empty and unplugged, prop the door open or it will stink.