I must bow out when it comes to hogs in snow!
I bet if you find a peat bog that doesn't freeze solid the hogs will find it too.
Another place to look is IN THE CREEKS!!!! They will root 2 feet deep water for the tubers of some lily varieties. ATTT mentions ribs... You will find that most migratory feral hogs will have little in the way of rib meat where those living in close proximity to croplands will have more. I personally prefer to just cut the rib meat out from the rib cage and freeze it for use where small bites of pork are the norm.
Brent