I have two of those garages and they work great and hold to snow load IF ::::
You must take nylon rope and string it length wise on both sides of the roof under the
cover, Two lines each side of slope. This will stop the snow load from tearing your cover.
what also helps is to use the cheap insulated pipe covering, the stuff that is about
4 feet long and you split it down the middle, then cover all the top metal structure with
them, both mine have that same amount of frozen snow on them right now and are holding strong. Just some info for you, BTW and new cover only shipped to you
from them is $200
I keep one 66 Beetle in one and one 67 Beetle in the other
with power to both garages for the tenders and lights.
My garage sizes are 12X24
Approximant Life span 6 years
Another option in the future is to get the DOME type top.
Jeff