I have never used an outdoor car cover, so my concerns may be unnecessary, but
The thought of any cover, sitting on the paint, for months. being blown around with little bits of dust/sand/grit/etc under it scratching the paint the whole times gives me chills.
The other nightmare, is rodents making a home under there.
I would rather clean the car, give it a good coat of sealant and wax and let it sit.
Come spring, clean and polish it for the summer.
Besides, snow is the least of your problems in NC and I would risk rain over my other nightmares
