Tips on garage tents:
1. Keep the tarp TIGHT! The wind will wear the material into wrinkles, then rain and snow will over stretch the sags.
2. Tie it down with those stupid anchors, lag-bolt it to 6x6's, Tie it to whatever you put in it! The wind has nothing better to do than BLOW all day and all night.
3. Keep the doors closed at all time.
Doing these three things will help them last longer. I have used them, lost them (completely gone!), seen many rolling through back yards, cleaned up so many of these over the last 20 years it's crazy. (salvage, resell parts, scrap, and get paid to make them go away)
The latest one I have is a 12 x 13 x 20 gothic arch model by shelter logic. I gave my daughter 150 for her frame, and found a replacement cover on marketplace for 200 (lady bought it and her husband went with metal roofing). Since I already had 6x6's milled out, I used them for a base and screwed 2x6's along both sides for alignment, before setting the tent on and lag bolting it down. I also drove oak grade stake deep in the ground and screwed them to the 6x6's.
If I can keep it tight, it'll make it til spring. It has already survived three major storms here in south central Maine, one storm recorded 63MPH gust(s) here on the home-weather-station.