Not a bad idea. Back when I was living up north, I haven't always been in Florida, a friend used scrap pieces of outdoor carpet to cover the windows on his car. He placed them pile side down outside the car. When frost and ice formed it formed on the carpet which made clearing the windows in the morning easy. He just pulled off the carpet pieces and stuffed them in the truck.
He didn't mention the effect
Old trick anyone living up north learns pretty quickly. You can use newspapers, carpets and even dedicated nylon coverings (that covers the entire car, and packs down to the size of a football).
On a cold, cloudless night, there is a great radiation loss from the earth's surface to space. Any object with a clear view of the stars will cool significantly. If
a) the temperature is below freezing - or even a few degrees ABOVE freezing
and b) the thin bodywork of the car (metal) and the glas windows cools below the air's dew point,
then ice crystals will form on those surfaces.
You can use basically anything - the ice will form on the outer layer of your carpet/newspaper/tarp or whatever, leaving your windows ice free.