Northern Ireland's departure would probably correlate with Scotland's, so more likely it'd be the United Kingdom of England and Wales. Catchy.

At that point Wales is probably east to call it a day as well.

Part of the problem is as the empire is shrinking London and England becomes more dominating. Each piece leaning reinforces this so I think if Northern Ireland and Scotland leaves wales will do so too. And perhaps even smaller pieces although that doesn’t look likely today.

Another factor is that Scotland stayed last time as border trade is the most important for Scotland. Not that UK is crashing it’s more likely they would leave.

"United Kingdom of Great Britain" is a lot catchier than "United Kingdom of England, Scotland, and — by the way — Wales" :)

Just Britain, these days ... if that.

"United Kingdom of not so great Britain"

Great Britain is the island, if it’s only Northern Ireland leaving all of the Great Britain island would still be in.

Fun fact: there is, in fact, a Little Britain—Brittany (Bretagne) in France, across the Channel from England.