I'm a member of large hunting club that puts on large scale deer drives. Need to be prepared for slowly freezing to death or driving the the length of a mountain for 2-3 hours. 2 drives before lunch and 2 drives after.
Do you wear rubber boots? If you do then swamp feet come with the package. About all you can do is carry extra dry socks when it gets real bad. And maybe a piece of old wool or fleece blanket stuffed in your pack that you can put over feet/boots when sitting long periods. I've also seen insulated over-boots designed to pull on when sitting - never tried them.
I grew up hunting in a club that did drives all day up in the western Adirondacks. So same issues in a area that gets a little colder. Carry a day pack so I can adjust clothing layers between sitting and driving, but tough to do for feet! We still drive, but usually not all day now.
Constant damp feet is one of the reasons I quit wearing rubber boots and switched to leather or leather/fabric boots with goretex liners. Most don't hold up very many seasons before liners start to leak, but still better for me than rubber boots.
For socks I still think good high wool content socks as thick as you can fit without being too tight are the best. I use mainly smartwool in different weights depending on weather and boots. When I did wear rubber boots cabelas carried a wool sock with a very dense, tight knit foot area and a looser knit top section that worked pretty well. The foot/ankle area was white wool and the upper leg gray. Similar to what they currently show as "Cabela's Men's 61 Series Wool Boot Socks"
I also gave up on liner socks in rubber boots. They'd fall/work themselves down inside the heavier socks because of the loose ankle/leg fit of the boots.
