There was a guy in Houston who had an inwall between his living room (I think) and the garage. Heat was his challenge in the summer months and cold in the winter, though Houston doesn't get as cold as it does here.
I would advise against a display in the garage or in any un-insulated space in the garage (ie pass through) just for the temp issues. It adds cost, one or more failure points, not to mention dust and contamination exposure.