Car cover for Irish weather

I have bought 4 car covers for my classic which is currently outside.The first one I bought was from Chameleon and had a felt lining with plastic outer layer and was heavy enough to stay put. Months of flogging in the wind will eventually break down these covers no matter how tough unless they are canvas. I do use elastic to keep it from flapping.

The later ones I have bought were all "heavy duty" but turn out to be useless. I go for the higher GSM spec but still they are lightweight and break down quickly. The last one was a Sealey "Best buy cover for 2021" triple layer, breathable, waterproof etc. but when I opened it it was very light and very thin so three layers compressed into nothing. As I put it on the car the breeze just lifted it straight off.

Where can we buy a decent heavy cover that will not blow around - preferably canvas?

Cheers