re: Santorini Greece

My 2 cents- 7 days is too long for Santorini. Try to catch a ferry to another island if you can. Naxos is less than 2 hours away by ferry. You can relax at the beach or explore mountain towns there.

Santorini is beautiful, and May is a little before the summer crowds hit. We rented a car from Hertz at the airport. I don't remember it being crazy expensive.

Spend a day walking the streets of Oia. Have a fresh seafood lunch and a Yellow Donkey beer at Ammoudi Bay.

Take a small day cruise around the island, still may be a little chilly for swimming off the boat, but you can visit the hot pools on the small island inside the caldera.

We drove to the southern end of the island to see Red/White beaches- it was kind of a let down. If you have a car, drive the length of the island around the caldera side for some awesome views.

Have a nice dinner with a Caldera view. Doesn't have to be in Oia- Fira and Imerovigli have great restaurants with awesome views.

As far as water/toilet paper, you have to brush your teeth with bottled water and can't flush TP. In our apartment you could smell the ocean when you took a shower. The TP situation was not as big a deal as I thought it would be. There is a small trash can next to the toilet for the paper.
TMI: the food is so clean there you won't have to wipe much