Greece is probably better off siding with Russia, they will get the benefit from the gas pipeline, have a market for their agricultural produce without other competing EU members due to sanctions, a weaker currency boosting tourism and exports. Staying with the Euro they will just have perpetual pain.
A gas pipeline? To what end? Greece doesn't need much of it. The customers Russians want are in the EU, with Italy first in line. I'm not sure many European leaders would be pleased to pay the Greeks to buy Russian gas, especially since that it would be a way to bypass Ukraine, giving Russia an even tighter grip on Ukrainian economy.
I agree that a cheap currency would help exports, sadly Greece doesn't export much. Anyone here likes ouzo? I don't.