Rangers (known out West here as Ronald McDonald boots)...

I've used them down to a true 15 below in Maine for 6+ Hours in a tree before killing my buck. I sat for just over 8 hours one day @ +20 before a guy stalking shot a small basket buck about to walk into view! Disappointing sit that was! Waterproof, durable, steel toed. NOT RECOMMENDED for climbing the steep hills here in the West but in a stand and getting to and from with little scent and keeping dry is good.

I recommend a Poly sock liner

and then a Set of Wool socks or other wool of your choice.

YMMV, but that's my $.02

REM7600