Great article Neil.
Because there is no closed season here in Iowa I fish throughout the winter. Provided it is not too windy or bitter cold. I still wear my breathable waders but wear aqua stealth boots in place of felt. Although I try not to fish when its windy or too bitter cold (19 degrees has been the coldest) I still stay warm in my breathables. I think a good base layer of moisture wicking underwear and socks is the key followed by wool as Neil has suggested or fleece.
Dave
" If a man is truly blessed, he returns home from fishing to the best catch of his life." Christopher Armour