Great article! Thank you for posting it. I get really cold feet, and used to suffer badly until I discovered down bootees. They are the best investment ever!
I agree about changing your kit when you retreat at the end of the day. A change of clothes in a dry bag has made a real difference on a number of occasions when I have been out in terrible conditions all day. A couple of times I have been so cold at the end of a day that I have used my platypus as a hot water bottle. As a safety measure, not being sure about it holding hot water I have then put the platypus in the dry bag from my clothes, as an extra layer. A Nalgene bottle would be great, if I carried one!

Down Booties... YEP. I have some Goosefeet ones with over booties for going outside.
And there is the down jacket for extra warmth.

And.. Have a hot drink, I find that helps too.

For me, the biggest leap of faith is to take off layers when you are in your bag and still feeling cold. I used to have a good laugh when folk suggested using spare layers as a pillow. Spare layers? I didn’t have any. Now I have learned that, slightly counter-intuitively, taking my jacket off will warm my feet as heat can be redistributed throughout my sleeping bag. Of course, now I sleep with the love of my life: a custom-made PHD bag – brilliant.