This BBC story suggests that the EU are pushing for a different Brexit deal for Northern Ireland than for the rest of the UK. This could be an enormous fillip for the NI economy as UK businesses seek to set up in NI to get access to the EU.
It could also mean that NI becomes the focus for smuggling, people and/or goods, into the UK.
http://www.bbc.co.uk/news/uk-politics-41183041
I think something like this will be necessary. Northern Ireland is a special case and EU recognizes that to the fullest extent. It's also beneficial to the UK. If there is a cliff Brexit that is somewhat cataclysmic to the British economy, Northern Ireland may well vote to join the Republic of Ireland. It's clear a referendum will be demanded and it's a tad difficult to see London prevent it.
This is relevant, I don't know if it was posted here before or not:
https://www.indy100.com/article/are...-northern-europe-really-in-the-uk--eJ0axHCqmx
McHrozni