Ambient Temperature Range for Printer Storage/Usage
Printers are electrical machines. They don't like water, so they also don't like condensation in them. If you can keep your garage dry and prevent a sheet of metal inside it from rusting, then your printer might survive the problems the shifting temperatures induce by condensing water vapor on the electronics.

Another thing to consider is, that at negative degrees Celsius, your printer might trigger a mintemp error, as the minimum temperature allowable is usually defined as 0&nbsp;&deg;C or higher. On the other hand, low temperatures might allow to bridge further than other days, as the cold air absorbs the heat from the prints faster. It could cause other problems like clogging or under extrusion due to low temperature though. 

High summer temperatures might impact the print quality, causing quite some extra sagging.

The Filament on the machine in a garage might be impacted because of the humidity changes, but might be mitigated with a drybox.