One thing to try when sitting in a stand ... if you walk in a long ways, expect your feet to be sweating. If that is the case ... I carry a spare pair of high quality wool/poly blend socks in a 1 gallon size freezer zip-lock bag and a few lens wipes.
My cold weather boots are Danners, full leather with 1000 gm. Thinsulate. I remove my boots & socks. Wipe my feet of with one of the "clear lens" wipes (which are achohol soaked). Put the fresh socks on. Attach "toastty toes" and slide my feet back into the boots. I leave the boots loose so that I do not restrict the blood flow.
It seldom falls below 20F where I hunt in SE Ala. The coldest I have had to deal with here has been about 7F. This methid of keeping my feet warm works fine for me. I imagine that in sub zero the boot blankets would be great to have.