I have stated this countless times
its NOT the amount of insulation in a boot that should be looked at for keeping feet warm
as if you have too much insulation and you walk in and feet sweat, your feet will get cold!
defeating the purpose your trying to achieve !
your best way to keep feet warm on ALL day sits in stands is this IMO
(i have spent many 10 hour sits in minus 20 temps)
wear in lighter boots for walks in!(actually I will add this, DON"T WEAR ALL YOUR GEAR IN< dress as light ta s you can handle it, and CARRY your heaver warmer gear in, it keeps you from sweating which is what gets you cold after your body cools off from the walk in, it also keeps unwanted moisture out of your WARMER heavier gear, that builds from your HEAT your body gives off while walking in), also , when you get to your stand, remove ANY and ALL clothing that got sweaty/wet, it will only make you cold as sit)
carry extra socks, (and any other gear you typically get sweaty on way in, a dry bag can be used to store sweaty gear if your worried about scent issue's))
next INVEST in BOOT BLANKETS,GOOD socks, too!
when you get to your stand,
THEN remove your boots,
let them AIR OUT!, and DRY inside!
then remove the socks you wore in, replace with GOOD warmer heavier socks(if they will fit in your boots with OUT being too tight you don't want too tight ANYTHING to prevent good blood flow)
MAKE sure inside of boots is DRY before placing dry socks and feet in them!
once that is done, place feet/boots on or OFF< in GOOD boot blankets, if you need extra warmth, buy heat packs and add inside boot blankets

NOW for cold hands, I again do not like thick heavy gloves there useless when you need to shoot, to bulky and well again hands sweat too
so again, walk in Light weight gloves,
get to stand, again, let yourself cool down! THEN replace again any sweaty gear/clothing
re dress(yes extra work, but? if you want to stay warm, it works)

replace at stand with lighter weight gloves you can shoot with, and use a hand MUFF, same like the boot blankets, if very cold out, adding a heat packet to inside the hand muff, and your hands will stay warmer than with heavy weight gloves , yet time to shoot, you can still do so!

as said,. YES this si extra work, more gear to carry in, more work to get changed at stand and blah blah blah, HAHA< BUT, I simply go in extra early, allow time to do all needed, and have sat in some super cold tree stands and blinds/ground set ups for 10+ hours for weeks on end,
it has been the ONLY way I have found to be able to do so!
YES 100% having GOOD gear is also a big part of it, but good gear alone will never undo the damages of having been sweaty from the walk in and then sitting in cold air all day long!
sweating is the start of the end all IMO!
maybe if your in super tip top shape, you won;'t or, have super short walks in, but if not, the above will serve you way better than buying super heavy insulated gear that will just make you sweat faster and won'rt really keep you any warmer once your wet close to your skin!