We skipped using the grommets almost completely on ours, Miss Bee. The doggone things are never exactly where you need them the most, and I'm too lazy and un-talented to put new ones where I want them. So we just use the grommets on one side - the anchor side on the west - and then use heavy spring clamps on the rest. Having it anchored on one side allows us to pull the other sides snugly into position, then we just give them a roll or two to fit and clamp them to the cattle panels. Man, that worked slick last winter. On nice days we could just unclip, roll the tarp as much as we wanted to allow more air exchange in and out, then re-clip to the new position. One wintry day our winds were gusting to 72 mph and they held totally and beautifully. I really like the flexibility this gives us to take advantage of more balmy days and protect when it's really nasty. The adjusting doesn't take but a few minutes, so we aren't out there freezing our hineys off fiddling with it, either.
I'd love to do the "wings" like you have, but I know there is no way I can do it here. Our situation is totally unique, and our needs are special for our area, and geared especially to my little feathered friends who are totally different than anyone else's feathered friends and .....and.....