The notion of temporary exit from the Eurozone is a nonsense. It is just a way for Germany to push Greece out definitely. 

Out of the Euro Area and willing to come back implies that a country has to dramatically reduce the imbalances that led to its temporary exit in a environment which will not be the one of the common currency. With its new currency its interest rates would be much higher.  

Efforts to be made to satisfy Eurozone criteria would be too important. The temptation would then to make efforts to take advantage of the devaluation of the currency in order to reshape the economy. 

In other words a temporary exit is a polite manner for Germany to “fire” Greece definitely. But would Greece be an isolate case or the first of a long list?