Here is the ADCO 32812 Designer Series Tan/White Tyvek Class-C RV Cover on an 86 Toyota Dolphin.
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This is made for a 20 to 23 foot Class C and as you can see it is plenty big enough. There is a lot of it on the ground, that's going to get dirty. But at least I don't have to worry about tire covers.
They recommend walking on the roof and pulling it up. I didn't want to do that, so I used a ladder. It's not all that heavy about 25 pounds. I tried to arrange it so it would fall down evenly, and it did; upside down. The wind is not your friend with this job. I'm sure I'll get better at it with practice.
I really don't know if a cover is going to do any good. but it will make me feel better when the weather is really nasty. I did something for my baby and that's about the best I can do.