As history has shown us, no monetary union has survived without a corresponding fiscal union. 
Time for the EU to realize this and prepare for an orderly unwinding of the Eurozone for members who cannot meet its strict budget discipline rules much like what Germany recommended for Greece in 2015. Poland, Czech, Hungary, and Sweden are purposely delaying adopting the Euro because they want control of their currency and can't submit to the budgetary discipline. Italy, Spain, France, Portugal, Cyprus and Greece should all do the same thing as the budget discipline is leading to austerity which in turn is leading to extreme parties and the rise in populism . To put it in perspective, could you image if in Canada, the federal government never sent fiscal transfer payments to Quebec, the Maritimes and Territories? How long would it take until they all left the Canadian dollar. The Euro is over and they just need to realize that.