Trick with sitting in a stand is to keep blood flowing to the extremities...this can be done with Isometric contractions. The biggest muscles in your body are your thighs, get them working and the blood will keep circulating. When on the stand in a seated position, just raise your legs up so that your feet lift off the floor about an inch and hold that position for a while. This gets your muscles worked up, meaning heated up...then put your feet back down and wiggle your toes for a while.
If you do this for 15 minutes, your feet will be warm for a while. You can tense up your core muscles off & on too. All this muscle contraction creates heat, but at the same time doesn't make any noticeable motion. (same motions will keep you awake in church, catholic weddings, operas or any other activity that you find yourself sitting for extended periods
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The only thing I wear all winter here in WI is uninsulated hiking boots or uninsulated LaCrosse knee boots. One good pair of wool socks, and if it's cold (for me that's 15°F or less) and I'm sitting, I'll pull out the Arctic Shield boot insulators. These are one size bigger than the packaging says, and they have plenty of room to put a hot hands in there if it gets to -10°F or so. (above that, and my feet will sweat in the insulators with a hot pad in them; wet feet = colder feet!!!)
For you, if its 30's and you are wearing 2000gr insulation, maybe your feet are sweating way to much on the walk in and that's why they are cold all day. Try uninsulated boots once, and put the boot insulators on when you are in the stand.