I think a, Scottish referendum would have to be won 50+1% and accepted before we got any leeway here. After all brexit fucked us all over on a 51.89 to 48.11% basis.
Brexirt is a red herring. People were lied to. The vast majority had no idea actually what they were voting for. I spoke to expats in Spain who voted in favour of brexit
and now can't understand why the Spanish are kicking them out! Crazy. Unification referendum is far more clear cut. Everyone knows what they are voting for. They might not grasp the ramifications of that vote, but it's much easier to explain. Scottish referendum is also different in that you got an entire nation that will have to go out on its own, where as here the majority of the island is already standing on its own two feet, and that includes parts of the North as well. Plenty of ground work to be done all the same.