The problem you are having is kind of common. On a class C most of the time the water from the roof of the cab over will run off the roof and on to the front wheels. Washing the grease on the slides on the front calipers on both Chevy and Ford. So they freeze up. If you take the front calipers apart clean them and lub the slides with a good grease the problem will go away.(Many auto parts shops sell small packets of grease just for slides and they sell for about a buck.)
The best cure for the problem after that is always cover the front wheels with tire covers when parked. They keep the AC, rain, frost and dew water from washing the grease out. They are not for sun only on the Class C with cab over beds.
Also never set the emergency brake when parking for winter. They will often rust and not release. Just use wheel chocks,blocks, rocks for you winter storage.
These problems show up most in areas with lots of rain like this year. Or hot areas where you are running the AC all the time.
