yes at this time of year unless you have a warm garage is a no no, the condensation that is generated just smears and it'll only get worse the darker and colder it gets.
Get a good wet spray on wax for winter. Turtlewax do a good one. Nowhere near as good as hardwax but strikes a balance between polishing and not polishing!! Just allows the water and muck to bead off that bit easier, meaning it wont need a good polish until early spring