I am going thru a similar problem and feel for you.
I keep my very rare(1 of 17) 1993 Daytona Iroc R/T's in a similar structure and have had the wind catch it and flip it over an 8 foot stockade fence,and yes it was strapped down with binders.picked the tent,2 tires and rims filled with sand and a 24 foot extension ladder that it was bound down with it.
The last storm we got last weekend dumped 12 inches of snow real fast and broke the camels back as I am now leaving the car outside where its safer.
No damage but now I am really thinking of selling my little Turbo monster as I hate seeing it sit out in the elements.
Good luck
And yes I am really sick of winter
Doug