Volvo C70 - Winter car covers - Hinch

I have a 2010 Volvo C70 which has been treated with GardX. I do not garage this car and do not run it during the worst of the winter weather, (i.e snow) as I also have a Suzuki Jimny. During the worst of the winter weather should I consider protecting the Volvo with a car cover as can be purchased on popular auction sites? Will this cause any damage to my paintwork? Will it cause condensation to form under the cover which may damage the car? Should I just leave it out there naked to suffer the winter weather? Any comments or experiences please?