Mark is probably right about the snake slowing down normally for its first winter.

Patches of dry dull scales that are truly rough and wrinkled make me nervous about fungal dermatitis. If you are sure it is not retained shed, and you don't believe it is an injury or scar, and especially if it persists for more than one shed cycle, I would get it checked out by a good herp vet.

Letting a snake with fungal disease brumate can make matters worse.

Can you post a picture of the area?