Living in the Alps, at the same altitude as Snowdon, I have a full cover for my car,but if it gets covered in deep snow it is just as hard to clean off - if it is not too heavy, I can pull it off. I have bought ropes that are easy to unknot, as trying to take apart frozen knots with ski gloves on is quite hard.
My worst nightmare is having to put on chains - I have to carry them in the car by law, but they are murder to attach. As I have a 4 x 4, I can usually manage without them.