Have been doing some google searching and this thread came up. We're looking for basically the exact same thing and finding it quite tricky. Have you had any more ideas/success? We're looking at beginning of July 2019 so not got as much time to play with. Again looking at Greek Islands and Croatia mainly.
Still really struggling to find anything which fits this, only thing we did come across was on an island in Croatia - it's called Levan. Google it - thus far this is the closest we've found to what we want but does seem to come with some logistical complications due to its location.
Let me know what you think!