Mark
I store two cars in a attached to the house and not heated type garage also. In gets cold in there but never gets much below the low 40's
I will add that this storage area is not the same one used for the drivers, so the door is rarely open in winter.
I run a small house dehumidifier all year long. I only set it about a third of the way up on the dial.
It has done a nice job, especially in the summer.
Something you may consider ? I got mine at one of the box stores.
Mike