How is it like being a northerner living in London/ the south ?

I am from NE England and have lived for many years in London and the South of England.

It is no different to living in the North (apart from warmer weather). There is the same mix of people. Londoners are harder to get to know but they make good friends, once you get to know them. In rural areas, people chat to strangers the same as in in the North.

It's like being in a cesspool. Don't come, Stay away.

How is it like being a northerner living London. Its like a northerner living in London. What you really mean is WHAT is it like being a northerner living in London.

Much the same as living in the North.

You’ll be seen as exotic.

The country is very multicultural, so regional variations of the UK native born residents are more easily integrated.

Even the Irish/Scots/Welsh have integrated well, and over many decades.

I'd not stress about this - hardly any native Londoners or people living in the South, actually live IN London these days.  Prople there may find your accent, it it's a strong one, just as hard to understand as any other non-British person living in London.