The funny thing (well, not really funny, but given the situation there is something that borders on humor) to me is that England is absolutely adamant that Scotland can't secede from the Union when that is exactly what they just forced Scotland to be a part of with the EU. It boggles the mind how they twist themselves into the weirdest illogical pretzels arguing that when Scotland voted to stay in the Union that vote was binding even post Brexit, as if the circumstances haven't materially changed.
We'll see how that one ends.
But eventually the only thing that matters is the economy and for now that doesn't look all that good for the UK, the sooner they turn around the better for everybody. But Europe is not going to push for this, it will have to come from inside for it to work.
Also, I think the idea that all that matters is the economy is glib nonsense. Whether people should vote with their emotions matters little, when they in fact do vote with their hearts. My own feelings on Scottish independence aside, I wonder if the Scottish Nationalists would have had more success in the last referendum if instead of making an (IMO rather weak) economic argument, they had stuck with the more emotional case for independence. "Yes, voting for separation from the UK will make us poorer for a time, but it'll be worth it to <sound of trumpets> be free."
I am from a place that impoverished itself for most of a century via independence, but I don't think many of us would vote to back with our old imperial masters now.
Nationalist sentiments ('free') are obviously going to have to take a backseat to those. So I don't see how a referendum on that using the dual theme of being 'free' and then immediately joining the EU would work in practice, that sounds like arguing both sides at the same time.
In the EU nobody cares if you make bad political decisions at the local level, like in Poland or Hungary, but once you create 4 years of painful Brexit negotiations for all other countries involved, then people care about you wasting their time.
But Scotland and Ireland don't really benefit from 'The City' and as such lost a lot more than they gained. These side effects, conveniently ignored by the 'leave' camp come with a major cost attached, which will likely negate all of the gains.
And then there are still the questions of internal borders, Schengen and the Euro.