I purchased my MH in December as a fixer with dangerously degraded roof seals, so I bought a cover to get through the New Hampshire winter without water infiltration. First we had snow - no big deal. Then, we had freezing rain - huge deal. On top of the cover was 5" of mostly-frozen slush, topped with 1/2" of solid ice. This frozen mass was (and two months later, still is in places) firmly attached to the fabric cover. With a bit of research, you could closely estimate the weight per square foot. I didn't bother. On a bitterly cold day with 35 MPH winds, I tied a rope to the cover and anchored it to my house, ten feet away, climbed on top and painstakingly broke the frozen cake off in pieces. The rope kept the cover from blowing into the marsh behind our house. I drove the motorhome to a local shop (with pre-arranged appointment to be driven directly indoors) for roof repair. Since then, we have easily received another two feet of snow, which has been easy to carefully sweep off of the roof with a soft broom. It doesn't stick to the roof like it did to the cover.
I will not put the cover back onto the motorhome unless I am having a water infiltration emergency. We know, from painful and expensive experience, that fabric covers enable rodents to climb up the inside of the cover to the top of the vehicle and enter through vents, etc., that they could never reach without the cover. We really want a huge barn/garage, but will probably begin with a carport that can be "upgraded" into a garage over several years.
2000 Holiday Rambler Endeavor 40PBD
Freightliner XC, CAT 3126B