I don’t believe that the potential dissolution of the UK is anything to be worried about. I think that the world reached its peak of empire building with the Soviet Union and the EU. It would seem that the nation state is the largest that people can be grouped together and still consider that they are ‘one people’.
The great empires all came and went. Gold was the glue that bound them, but absent
that, they were doomed. Some were broken
in battle, but many, such as the British and the Habsburgs, essentially broke
under the weight of their own cultural contradictions.
Wales, Scotland and N.I. are their own entities and I don’t think that England needs fear invading hordes of Picts and Celts anymore. Free trade and open border agreements should not be hard to negotiate. It would also serve to invigorate the notion of cultural identity that could serve to stem the tide of alien arrivals.
English life is forever changed, but then it was always an evolvement. Current circumstances demand a faster evolvement, but if immigration is stopped right now, then it may still be possible to forge a new and acceptable idea of what constitutes an English person.