I have a mesh cover (Coverlon I believe) that we left on all winter. At times, there was about 2 feet of snow on top, other times it was 6 to 12" of ice. Our water level was initially dropped below the skimmers, but here in NY, unless you drop 2 or 3 feet, it comes back up. So we started low but by the end of winter our water was better than 1/2 way up the skimmers (good thing we had the crushable pipe blocks in place).

Anyway, the cover has heavy duty springs that allow at least 6" of travel, so that is about 12" total. The cover seemed fine, I didn't notice any loose seams or wear marks. Our cover tie downs are about 18" back from the pool, the actual cover extends about 9" back.

The only issue we had was when we opened. I had to tighten the cover in order to lift it up off the water so all of the stuff on top could dry and blow away (which it did). There was a lot of silt in the pool but very little large stuff, so the cover did its job. As for the big pillows, I have thought about putting some in, but I'm not sure that they would really make that much difference.