The infinity pools are not heated. I believe the heated pools are the individual pools in the newer section of the resort. We had an infinity pool that had sunlight shining on our pool till 5 pm which made it warm enough to tolerate entering the pool in early August. I don't know if that will work for your late September stay. Definitely eat in Plaka to save some serious cash compared to the resort. We had no choice but to leave the hotel at 7:30 am for a 9:30 am flight (taxi strike, hotel arranged a bus). I was very nervous but we made it. I don't recall the airport having horrible lines or slow service or else I would've been ever more on edge. I was just nervous because of the time.