forestwalker
Bushcrafter (boy, I've got a lot to say!)
I think some of our Scandinavian members speak highly of Nokian rubber boots with felt liners
http://www.jmcaleer.com/index.php?p=product&id=608&parent=25
The nokians are
a. quite warm
b. soft and comfortable
c. waterproof,
d. waterpoof, so you will need to keep an eye on interior dampness
e. don't believe the "-40 C" claim unless you wear plenty of socks inside (I wear 2-3 pairs of thick socks inside mine, that was barely sufficient in -40C
Get the version with removable liner, and buy a spare. Be prepared to work on keeping them dry inside, take the liners out at night, put a handwarmer inside them at night, etc. Someone I talked to claimed to have used a plastic grocery store bag as an exterior vapor barrier outside te felt liner: easier to dry than the inside of the wellie itself, but I have never tried this myself.