I think that's a good observation. People from Northern Europe (Sweden, Norway e.a.) are also known to be "colder" and more reserved than people in the Mediterranean region.
People in the north of England are said to be warmer and friendlier than those in the south. The north was mostly industrial and rural whilst the south has London's financial district and the Home Counties where the "posh" live. I say was because its a lot more homogenized now and there's less industry.
I think any general north-south variation would have to be over large areas (Brazil, Europe, the US). England is tiny--of course north-south differences are going to be dictated by local factors.
