I don't have any experience in storing in the snow. But... just draining the water is insufficient for winter storage in much of the US and all of Canada. Even a compressed air blowout of the fresh water system is insufficient. If you are concerned about snow, then do a complete winterization of your camper's plumbing system. A camper under a good cover should be OK as long as you brush the snow off from time to time. I'd tilt it slightly nose up just to keep water from running up the roof overlap.
2012 Rockwood A122S
2008 Toyota Tundra Double Cab 4X4
Former owner of a 2002 Coleman Niagara GTE