How long can a car stay in garage if temps drop below freezing

I guess it depends on the garage....My attached garage with my Barracuda stays above freezing as long as the temps are above 10°F. If it goes single digits in will drop below freezing in the garage (I keep a thermometer on my car all winter just to monitor the temp in there). Since it is connected to your showroom, I would think it would be OK...but if you are worried about it, move the car in the show room :).

By the way, it is currently snow/raining where I am :-(