Had sustained winds of 74MPH that took our sunbrella cover off.
 

Had a HUGE WIND STORM our strapped sunbrella cover came with straps. In addition we used some rope. We were fortunate that it didn't rip and stayed on our property. The roof was covered in strips of bubble wrap and then we used blue painters tape to the fiberglass. This all blew off. The only thing I can think of to wind proof this is huge ratchet straps. Need to measure and then find a source for big enough straps. Hopefully no dammage to the roof or any part of the HI Lo. I have a NYS inspection apt. March 15th. DH will put the battery in and raise it up. We choose not to cover it again as it is a lot of work. Of course we had eight inches of snow on the RV after the cover came off. Sprig where are you? Open to discussion solutions to this problem.

Wow! Good thing you recovered the cover and it was not ripped. The only ratchet strap lengths I know of are 15 ft, but you could always hook two or more of them together to get 30 ft or more. I'd think a strap near each end would do the trick. You also would not need to run the strap completely under the trailer if you could hook it to the frame near the bottom.

- Jack

Ratchet strap ideas
 

Thanks for the ideas. Will run it by DH. Didn't know you could put two straps together. I could possibly also have my local boat/awning fabricator sew some straps together. I am determined to take this problem by force. We also lost power during this storm for 6 1/2 hrs. DH and DD got to campout in the house. The temp was 57* with a kerosene heater on. I was feeling guilty as I was in the hospital with warmth and cable TV. We lost a small section of our roof shingles. Waiting on the roofer to get up top and give us an estimate. Probably will get"skunked" as we have a $1.000 deductible. We just have one layer of shingles on. Will watch in the attic for leaks. Many in the area suffered dammage/insurance claims. It was to our benefit that the HiLo is stored away in a low profile position.

Our Home Depot sells the same straps that low boy truckers use, as Jack says, about 15'. and ours is a small HD. Maybe your DD could check the stock and get lucky. In SW FL, we know about those winds.
Tree

truckers straps are available in 25' lengths 2" width

$15 at Harbor Freight, also available at Tractor Supply

Thanks for the replies
 

I also was thinking of HD,Harbor freight. We have a tractor supply that is about to open up in our area. Will do a search on the internet.

Any truck stop should have longer ones as noted above. They also go 30’ and beyond as well as 4’ inch wide variety

I have a sunbrella cover that I have used for 12 years. It's still in great shape and has been through many high wind storms. We live across the street from Lake Erie and the trailer is stored next to the house. In addition to what has been suggested, I split a swim noodle and place the strap inside to protect the cover where the strap goes over the edge of the roof, or any other sharp areas it might come in contact with.