First of all our houses are insulated, heated and we have double windows. The fact that we do not feel cold all day helps to mitigate the outside cold. Layers are key. Long ago I learned that fashion doesn't matter when it gets cold. As a high school student I went out with knee socks and a tunic which stopped just above my knees. It didn't matter that my coat was long and my boots were high, it was COLD!
Now I wear long underwear when needed and a couple of layers on top. Add a warm coat, scarf, hat and mittens (not gloves) and I are well insulated. If the wind is bad, I'll add windproof pants. We all develop strategies of how to wear it all, with scarves up over the mouth, a hood up and techniques for turning so you can properly see the traffic and not just the inside of your hood.
Next comes warm boots. If the feet and head are warm everything else seems to feel warmer. So for those who think we suffer in the cold, I know that the dampness in London can sometimes feel worse. And the lower the temperatures here, the more it is likely to be sunny. And that always puts a smile on my face - adding inner warmth.