I understand that infrastructure is more important to be able to cycle in the winter, even eclipsing temperature in very cold areas. I live in an area where there is no bicycle infrastructure, I'm actually 100x safer riding my motorcycle well below freezing on the road, than riding my bicycle on a beautiful fall day. And I do, I have gear for it .There are cities though, where temperatures don't regularly get super cold and people don't actually have the clothing and gear to cycle in the winter. I would guess in those areas, temperature is more of a factor. In areas where winters are consistently very cold, people already have what they need and are able to cycle if the infrastructure is there.