I was checking on some deer stands for next weekend recently. Its some of the same area I pheasant hunt after deer season, and its exactly how you described it there too: flattened. 3-4 inches of heavy wet snow completely eliminated 75% of the bird habitat already. It looks like a heavy brush cutter went through the entire countryside of grassland. Total buzz kill.
This specific spot was one of my better spots last season because the grass stayed intact all season, all the way through December. Now there's just very isolated clumps of heaver cover and trees.
The other thing I noticed was the abundance of standing corn too. They've started on it, but there's at least half if not more still up. And given how wet it is with more rain coming, that won't be going anywhere soon now.