I would like to posit that there isn't so much of a North / South divide as City / Country divide. If you go to any of the major Northern cities - Leeds, Nottingham, Newcastle, etc. - people can be generally groovy.
However, venture out of these population centres and that's when you meet all the stereotypes.
Having said that, I'm quite a typical snobby Londoner in many respects and when I go to the shop to buy a loaf of bread, that's all I want to do, I don't want to have a conversation about it with the check out girl.
There was a great gag from a London Stand Up years ago about going up North for the first time. Someone he didn't know came up to him and said 'Hello'. He didn't know how to handle it, so he stabbed him.