I live and work in north Japan were we have had over 15 feet of snow this winter.  The temps average about 20 degrees during the day and about 10 degrees at night.  I work outside 50% of the time, and the other 50% inside.  I was issued boots when I got here and they were the worst boots I had ever had.  I ordered the Sorel Conquest Boots and was very happy with the design and craftsmanship.  The boots keep me dry and warm, almost too warm.  The boots will make your feet perspire therefor your feet get wet and that leads to another issue.  Overall I was pleased with the purchase.