Check out the tirerack test writeup for a few AT tires:
https://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=240
For an AT, IIRC the Cooper AT3 4S did well as did the new Bridgestone Revo3. In previous tests, I recall the mainstream hardcore ATs such as the BFG and Goodyear did not fair as well in the snow. Snow needs more siping, and AT tires tend to have larger lugs and less siping. For this reason, a tire that's less AT-biased and more highway/all weather biased would be recommended for snow work.
The newest version of the Firestone A/T2 has more siping than the last gen. There's a lot of diehard followers for that tire.
I've just picked up the newer continental TerrainContact AT. It is NOT well-reviewed for snow, but it's quickly becoming a favorite for me. They have a hwy version of this carcass with more siping which could be spot on for what you are looking for: TERRAINCONTACT H/T and maybe the CrossContact LX20.
For snow - you want siping, not big lugs. There are others out there as well, but these are tires and brands I have some familiarity with. I am generally a big fan of coopers. They tend to use softer rubber in my experience which also helps when it's cold out.
Of course, weight in the bed is also a huge help. A buddy of mine used to put a couple hundred pounds of mulch in his bed in the early winter. Snow would soak into it and double the weight. Since it conformed to the shape in the bed, it didn't shift around. In the spring, he'd shovel it into his yard. He got around 100% just fine.