The Greeks do not need Germany to come bail them out. Russia was in something of a similar situation in the mid-1800s and resolved their financial and strategic difficulties by selling Alaska to the United States. At the time Russia feared that they had to sell Alaska or lose it to British Colombian expansion.
There are over 6,000 islands in Greece of which only 227 are inhabited. These 5500+ are all assets that could be used to satisfy Greece’s debts either by concession, Hong Kong style, or outright sale as Russia’s Alaska holdings were sold. At the very least this is an option that should be talked about. Strategically, a sale could be offered to France, Italy, or the UK (I do not believe the US would be interested) that would create interesting possibilities of introducing a buffer state between the remaining Greek Aegean territory and Turkey. The islands themselves may or may not be worth much but their economic zones, fisheries, and resource possibilities are intriguing.
The idea ultimately may turn out to be insufficient by itself to save Greece. But you really don’t know until you present the idea and so far nobody seems to be pursuing it. I find it odd that a proven method for raising money that does not require default or endanger the EU is not even on the table for consideration.