(Yes, I'm a cynic and once in a blue moon the Parliament actually seems to have some influence.) -----sapere aude
I can certainly envisage England leaving the EU, or not applying for (re-)admission. A lot of people outside England might see this as a good thing for the EU.
Also, the idea of an independent, self-governing Northern Ireland is quite worrying - given the total inability of the political forces there to work together so far. Necessity might be the mother of invention, to take a very optimistic view.