Have you allowed to build up on your rig before climbing up and clearing it off? Got real worried with 18+ inches of Sierra cement and finally did it. Wasn't easy but what a relief!
Way back when, I had a Newmar fifth that stayed north during the winter. We had some big snows that left near 4 foot of snow on the roof. Called Newmar and talked to one of their engineers who advised that that quantity would not be a problem except for the roof vents, particularly when melting started. Went out and shoveled the roof and felt tired but better. Now, being retired, i've found that it very rarely snows here in Florida.