Most long RVers would advise against covers because they tend to damage the finish of the coach more than the protection they might provide. Wind causes the cover to chafe and scuff body parts.
If you feel the benefits of a cover outweigh the potential risks, then you would want to tie down and tape any loose material to create a tight form fitting cover.
The covers sold in RV supply houses would be the kind to get, because the roof portion is made of Tyvek for strength while the side panels are made of a breathable fabric.
Using tarps would be ill advised, because of potential for condensation causing serious damage to your coach.
Other options to consider are building a roof structure to protect from snow accumulation or to find an indoor storage facility. Many RV owners simply leave the coach in the open, and wait until the ice and snow on the roof is fully thawed before moving the coach. The real risk is ice and snow accumulation that would create an excessive snow load on the roof, in which case the snow would have to be removed very carefully not to damage the antennas, the air conditioners, the skylight, the vents and any lighting.
If you were removing snow from a covered coach, you would want to be careful not to tear the cover, of course.