I'm really sceptical that this is as big a factor as some of the others, but I can see how it might be a significant factor. I've also lived in cold places most of my life, so I'm not in a very good position to judge. I feel like the biggest factor will ultimately turn out to be "that's how history played out", though. Looking back, it's not clear that the hypothetical dominance of the North was really noticeable until maybe the 17th century (I'm not entirely confident on this, so correct me if I'm wrong), so I'd be more inclined to attribute it to cultural, geological, and geopolitical factors. As an example, Greece and then Rome led the world in many things for a while, and they're pretty warm. So did China and many of its core areas are fairly warm as well.