If Trump is impeached (even though he almost certainly will not also be dismissed from office if so), it would be a first in American political history for an impeached President to be re-elected, so that would be interesting!
UK might give the pretence of leaving EU but the process will be so long, arduous and complex that many of its citizens will probably have lost the will to live long before it completes, if indeed it ever does.
Spain leaving EU? I rather doubt it but, were it to do so, do you imagine that it would take - or want or ever be able to take - Catalunya with it?
Holland cannot leave EU, as it is not a country but part of one (the Netherlands) which I very much doubt would want to leave EU, given its history within it.
Now here's a prediction of mine; Thalbergmad will somehow manage, despite his admiration and respect for Jonathan Powell's playing, to pass up on the tempting opportunity to purchase the 7-CD boxed set of Sorabji's Sequentia cyclica when it is reeased next month! Mind you, I've been wrong before...
Best,
Alistair