Have you thought of setting some anchors in concrete, and tying the trailer down? Or will the horses be in that field, and pose a danger to them?
We could, but I don’t think we NEED to... our bad wind storms are 40-60. Our really big one two years ago we had gust to 80. We rode that out in the truck... we don’t get the kind of winds that can pick up trucks and trailers, just the kind that can topple tall firs, particularly if their feet are muddy.