Europe's finances are in a bad shape, especially the so called "euro zone" If the union breaks apart, and some countries have already threatened to leave, euro will dive even more than rubble and hryvnia.
No matter what happens to EU regarding countrys leaveing it or being forced to leave, EUR will remain intact as a currency, and there is zero chance of it changing into anything else.
Threats to leave are a bluff, and even if that happens, it will happen on damage of leaving country, not on a union itself. Perfect example is Greece, what did they do to benefit EU? Nothing. It's better to loose them than to find them i say, and same goes for any other EU country that wanted EU privileges, but failed uphold their part of the deal, and to help with stability of the region.
cheers
