I went a different direction based on hunting a lifetime in Northern Wisconsin from open stands. The coldest I’ve ever hunted from a tree is -12f on an all day sit. It sucked.
About 15 years ago I bought a Heater Body Suit. Yes, it’s ugly, bulky, and not easy to put on in a tree, but it makes me bullet proof in the cold. You can wear normal light clothes for the walk in, including boots / gloves, put that HBS on and pop a couple chemical hand warmers inside. It’s all day warm.
It’s also surprisingly quiet and quick to get out of - for shooting.
When it’s not cold enough for the HBS I wear Sitka Fanatic gear and LaCrosse Ice Kings with a toe warmer. For less than all day sits, bow season, and hunting wet country on my feet, my go to has been Muck Arctic Extremes for 10+ years.