A friend and I rented a bungalow at Thea Studios, which was plenty of space for two people. It is certainly possible to sleep more people, as there was a queen bed, a twin bed, and a very large sofa. We had a nice patio with a sea view.
The staff was very friendly and helpful when we asked for airport shuttles and requested to rent an ATV.
Lovely pool and a free breakfast was included. Less than a 10 minute walk from Fira, and even faster if you drive!
I would happily at the Thea Studios next time I am in Santorini.