Here is what I wear......1 size too big is the best so you can move your foot around inside. I sat all day in these in Saskatchewan when it was -25 in the morning and highs of -3....plus a 20 mph wind. Had a toe warmer in the bottom, but they only last half the day, but my feet stayed warm all day.

http://www.cabelas.com/cabelas/en/templates/pod/horizontal-pod.jsp?_DARGS=/cabelas/en/common/catalog/pod-link.jsp_A&_DAV=MainCatcat20564-cat20574_TGP&rid=&indexId=cat20574&nav Action=push&masterpathid=&navCount=3&p arentType=index&parentId=cat20574&id=00208 33