You guys have it all wrong. I hunt from a blind every year in temps as low as -20f...and ive seen colder.
The trick is a heater! I get the inside of my blind to about 60f and am comfortable in standard leather work boots, blue jeans and a flannel shirt.
My problem is i get sick every year at camp...i think its the poor eating, lack of sleep and binge drinking. Stress of dealing with family is also a problem for me to be honest