Great and thorough article! As you said, you chose not to address the iron/activated carbon warmers here,(albeit keeping in mind that frostbitten, bare or skin compromised by poor circulation should not make contact,) but for photographers they are worth the bit of extra weight in your pack. They have various hours of effectiveness, so depending on how long you are out they can be of great value in keeping your extra batteries strong when tucked in their general area of your pack, while the one that will be immediately be needed next can be kept within layers closer to your body.
I have in the past experienced being able to get the few extra shots I had not anticipated staying out for by placing a hand warmer and the expended (by cold) battery in an extra insulated glove for a bit.
The note about testing the wind blocking ability as you shop, or dress is brilliant!
The only thing I might add for anyone working near water in such cold would be an oversize thin waterproof pair of gloves
when working tripods into positions or removing from or relocating in streams, ponds, ocean etc. Getting your hand protection wet in severe cold is not something you really want to do , especially if a hike out hauling your tripod is in the cards at day's end.
Thank you for thinking of us all...