It would be hard to beat the great white cedar swamps of northern Maine. Besides providing super thermal cover and a great edge to still hunt when flanked by alders, white cedar is reported as being the only single plant that can sustain a deer through the very long northern Maine winters. If cedar grows in your area of Maine, creating a white cedar stand in and along one of your swamp areas would be an awesome accomplishment. It would take a huge effort and seedling trees would need to be fenced for sure to get it started. Whiter cedar swamps though have been a key ecosystem for winter deer yards since "forever" and likely are among the best winter deer yard areas anywhere. Keep us updated on whatever thermal cover you decide to plant.
Chipdasqrrl, I got to tour a property in Michigan many, many years go ( actually not that long ago--maybe twenty-five years give or take a few) and the cedar swamps there were just awesome. The moss which was THE undergrowth of the cedar "forest"was so deep and cedar stem counts were so high I remember thinking that a cruising deer and a still hunter could pass within thirty yards of each other without sensing the others presence. It was an awesome experience to see such great cedar swamps as I saw in Michigan on that trip. They reminded me so much of the great Maine cedar swamps that I had still hunted thru as a very young deer hunter.