Lots of great advice already. I have a few setups. I get cold easily when stand hunting. Lot of times I have long hikes to where I hunt when it gets cold. I have Day one wool parka and bibs both with windproof liner and insulation. Very warm, very quiet, very heavy. Not my favorite to use on like hikes back because they are bulky and heavy. But one of my fav. setups due to quietness..I do like ASAT camo too.
Last year, I got the Sitka incinerator set because it is a lot lighter to carry in and packs down very well. It is very warm a little warmer than the dayone setup with same layers. I do get a little chill above my knees do the the compression as mentioned. I just stand up occasionally to warm up there...or I place to toe warmers just above my knees in a base layer pocket. That works great. Plus they are waterproof and great at cutting the wind. But and to me the only negative..is the incinerator is a little noisy especially up against some trees. I have killed a number of doe with a bow with the set...but it worries me and I have to move slow...the area it worries me the most is if I have to move to make a shot behind me or way off to the side. I know those deer shouldn't be there downwind of me...but it seems to happen to me a lot. It probably isnt a deal breaker...but compared to the dayone which makes no noise...if I know I can use the dayone...shorter walks or not as cold...I use the dayone set. Honestly both sets get a lot of use. Sometimes I wear the sitka incinerator bibs and dayone parka...that works great. This year I bought a sitka fanatic vest and I love it. Im going to buy the Sitka fanatic coat and try that with the incinerator bibs with fanatic coat and vest next year. I think there are a lot of huters that do just that setup.
I also have an IWOM. It is the warmest thing I have to wear. It is a little bulky and heavy...but it is WARM and waterproof. It isnt to bad to pack in though..the way it roles up. I dont have a problem putting it on in the stand and I use a lone wolf assault a lot. I personally like it better than the HBS because where I hunt, I dont think I can get away with that extra movement to get out of the HBS. On public land here the deer look for you in the trees and are skittish. I hunt with my bow sitting on my lap so I dont have to move to get it off a hanger. Plus there are too many times where deer are in fast or the opposite they come in slow and you get cold coming out of the HBS and waiting...Just my humble opinion. One big negative is...it is a little noisy..about the same as the incinerator set. But, I have killed many deer wearing it with a bow...I just have to move slow and carefully. The IWOM comes out in the nastiest weather below 15 degrees and windy for me. Having the wind helps reduce noise issues.
Because I hike back at least a mile on public and I skin and debone the deer and pack out. I have to have good leather boots. I wear Lowa tibets. To keep my feet warm wearing them I have to use the arctic shield boots. I hate having to pack extra in..but I have no choice. Fortunately the boot covers pack down well and are pretty light and keep my feet warm. I have seen deer catch my scent if they hit my track more with leather boots than rubber boots...but I just cant carry an 85lbs pack (deer meet, hide and equipment) with rubber boots. I try and plan my track to tree carefully. Where I have shorter walks on private land...I wear Baffin Impact boots...they are snow mobile boots. They are a little big..but they are the only thing that keep my feet warm outside of boot covers. Ive tried everything...2000 gram rubber boots, those funny looking military bunny boots...I still have a pair of the black ones...lol. Those Baffin boots are the real deal for warmth. My feet are the worst to keep warm. One nice thing about the IWOM..is I can wear my leather boots and not have to use boot covers.
I hunt a lot for deer. We have unlimited doe where Im at... I took 14 this year..I love to hunt. We love eating meat.
I have spent a lot of time and money trying to find a way to stay warm and comfortable. Hopefully this helps you make a decision with out having to try everything out. I have heard the FL sanctuary is pretty good too but maybe not as warm as the incinerator but quiet. I have some of there base layer stuff and its great. I just ordered a FL woodbury to try out when its above 35 degrees. Feel free to message me if you want any more detail.
For reference, I can wear most of this stuff up to 35 degrees (obviously lighter layers)and not get to hot...I think I get cold sitting outside easier than most...but I can go out in the cold in light clothing if Im active. I sit on average for 4 hours. I can do that pretty easily in all these setups at 0 to 35 degrees. All day sits in 5 degrees or so Ive only down in the IWOM and even then I used a few hand warmers. Good luck let us know what you do.