Probably one of the easiest things to do for winter cover, as well as year round cover, is to do edge/border cuts. Simply drop all trees 20-30 yds back from field edges, log roads, etc. It'll get thicker than snot, but, you'll have to recut them every 10 years or so to keep that edge.
Much as I hate to say this, I have an area that is thick with tartarian honeysuckle. Also have hawthorne along the edge of that. The honeysuckle gives a small berry. The grouse love it, and they like the little apples that come off the hawthornes.
I wouldn't plant the honeysuckle as its and invasive. Good cover tho, but spreads like crazy. Same with autumn olive. But, I know some on here will say plant the olive.