The fact that the Troika hasn't been willing to give one iota on the Greece issue should be enough of a reflection on how little consequence they think an exit of Greece from the eurozone would be. Germany in particular doesn't want to give any ground (I imagine all of the nazi-name calling has played no small part), but they're hardly alone, many countries are taking a very hardline stance on Greece. Most parties feel that the consequence of giving way to Greece could be significant, but the consequences of their exit - while not completely painless - would not be that dramatic.
On the other hand, in Greece, there's only one route for exit, and that's capital controls (or a rapid conversion over the weekend) where everyone's assets are converted to some kind of new-drachma, which instantly devalues to half its value or less. Which is why everyone is taking their euros out of the banks, they're not stupid (unfortunately, thieves aren't stupid either, breakins have become an epidemic as they look for people hoarding money at home).
I can't see a cryptocurrency helping in any way... if anything I'd guess it'd only serve to unnerve markets even more and lose even more value as a consequence. I could picture it maybe as a simultaneous and rate-locked currency to a physical New Drachma, maybe. But it sounds IMHO like an incredibly risky move even then. I mean, one presumes for example that there's a government-controlled master key to "print" more cryptocoins? Then that means that your entire economy can be crushed overnight by someone hacking, physically stealing, misusing, cracking, or whatnot your master key. Isn't that an unnecessarily big risk to take? And on an individual level it seems full of problems as well...
Don't get me wrong, I don't think cryptocurrencies are inherently an evil or shouldn't exist. But I would have serious second thoughts about such a massive nationwide rollout on a country that's already in chaos.