"Northern Ireland is part of the U.K. and will remain so for the foreseeable future "
Until the demographics tip over - there is a steady increase in the population likely to vote for joining the Republic and the Unionist numbers are steadily falling.
https://www.irishtimes.com/news/poli...orth-1.3891032
On the other hand I can remember having a beer with a well known Dublin politician 10 years back and he said "Of course everyone itneh Republic is in favour of unification - just as long as it doesn't happen in their lifetime. No-one has a clue how it would work out."