We have 2 of these from Harbor freight that have been up for 3 years. 2 Winters. I got universal side kits with a zipper door front off amazon. Both have held up well. No signs of deterioration as of yet. Ours our just sitting up with the ropes holding it down. https://www.harborfreight.com/10-ft-x-20-ft-portable-car-canopy-62858.html
To upgrade them I would lay a 2x8 treated wood frame on the ground first. Anchor the legs to it, then use ratchet straps instead of the nylon rope they come with to hold it tight to the ground. Ours are full of garden tractors. As long as the roof cover is tight, most moderate snow slides right off. If not you can just go inside and push up with a broom or something. They have taken a few wind storms and come out still standing.