A hood is mandatory.
I swear by Patagonia Capilene underwear. get the turtle neck top with zipper.
Also have som Marmot underwear which is good. If its good for the skiers its good for us cold weather waders.
Over the underwear a rag wool sweater, then a fleece pulover, then the insutlate wind breaker jacket with hood
Don't forget some Hand warmers which will last 7-8 hours.
Some Yaktrax or other strap on cleat for walking through the snow and getting traction on ice.
Two sets of rag wool or fleece fingerless gloves.
Lots to consider for winter fishing in addition to the rod, reel, and fish.
Also be very careful do not take the wading and trail climbing risks you do when it is warm and there is no snow or ice around.