I would definitely vote for a party stating that staying in the Euro is not going to be an at any cost objective - for instance, that is the Syriza position.

I would want my government (yes, I can dream - France is not going to do that anytime soon) to very clearly present that, if the Euro is to insist on sticking to something that arithmetically cannot work, then the decision will be to leave, and it will be taken soon enough.
But that we are quite willing to be part of a workable project if the appropriate changes are made.

It may seem unthinkable, but somehow I guess Germany would think twice before insisting on the path of doom should a country like France or Italy make a credible exit threat.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi