Correct and the breakup of the UK will likely lead to a United Ireland. The real question is what will England use for a TLD? They've never considered their place in the world that isn't in reference to the UK or GB because to them the two are interchangeable.
Things would need to be really, really bad for the Unionist population of NI before they'd vote to join Ireland. I'm honestly not sure that anything bar the total collapse of the other island would do it, tbh ;)
Things weren't particularly bad, and the UK managed to vote itself out of the EU and into recession. All you need is a single vote and a particularly apathetic populace to change the political landscape forever.
I strongly encourage you to visit Northern Ireland and talk to people (even just see the peace walls) as this is far more like the 18th century than it is like the 21st (in the sense that religion/ethnicity/history is the predominant driving force behind voting patterns).