OK here goes.

I live in Manitoba. by November we have freezing temps. You want to sit all day. Layer your body. I wear insulated bib pants and fleece pants under. I wear a fleece shirt and a jacket over. My hands...... I wear the same gloves from the beginning of the season to the end. I simply put hand warmers in my pockets and use them when needed. Feet. This is the tricky part. I wear BIG boots. Rated to -100 with moderate activity. Now with that being said if you sit in a treestand with a metal platform........ the metal sucks the heat out. I put the adhesive type foot warmers in my boots. One for toe and one for heal. Don't shake them....... they will heat up on the walk to your stand so your feet don't over heat. Another VERY important thing is to bring your boots in and DRY them out after every trip. That way moisture isn't present to get your feet damp when you put them on.
When I walk to my stand I have my jacket and bibs open. My bibs have zippers down the legs and I open those too. Don't get sweat up b4 a long sit. Heck I don't even wear a hat. I have my insulated mask in my pocket and a touque in another. First I just wear the mask and if I get cold I put the touque on over the mask.
Kidneys/back get cold....... sew pockets in your jacket and put handwarmers in them.



Works for me. I can sit dawn till dusk.