I'd carry a lot of cash... that you can convert in smaller batches in both Turkey and Greece I don't like getting cash from ATMs, bad fees and ex rates, security issues standing in front of a machine.

Use credit card for larger purchases with more established suppliers...ferrys hotels, etc. cash for queys, dock restaurants, etc like you did your last Greece trip.

I'm still working on a Greece trip for 2016 for my group. Still need that sailing certificate. Sunsail has an interesting promo in Croatia.

Look forward to a trip report from you!