Is it possible...?

If you are willing to fly, the distance does not matter that much. But since there are no direct flights between the Ionians and Cyclades, the transit is likely to take a whole day. You certainly won't be able to see much of the Ionians in 4 days because of poor inter-island ferry connections in that region. Cyclades are much better in this regard but 4 days is still very little. If your exit airport is Athens, I would leave Athens to the end of your trip. The risk of getting stranded is much greater on the islands than on the mainland.

Sati has it right. As long as you're flying you can make it work. But you really only have time for one island in each area. 4 days will fly by. I strongly recommend Santorini over Mykonos because there is a lot more to see and do there. And here's another vote for saving Athens for the end for the reason stated.

A lot could depend on which Ionian islands you want to visit. There are direct flights between Mykonos and Corfu. From Corfu you could also get to Zakynthos (short flight) and Paxos (ferry). Lots of things are possible but a lot depends on scheduling. In Sept many of the flights and ferry schedules are shortened and are only possible a few days a week, sometimes just once a week so it can be difficult. I think it's certainly possible to spend a couple of days each on Santorini and Mykonos and then fly to Corfu and base yourself there with a day trip to one of the other islands. I've not been to those islands but Corfu is on my bucket list and I know others that love it there.

The Sporades islands also have lovely beaches and natural areas. We stayed on both Skopelos and Skiathos and really enjoyed our time there. The flights from Mykonos or Santorini go through Athens so take a bit longer but ferry connections among those islands may be a bit better than the Ionians. Although, there again, you have to carefully check shoulder season schedules before making any plans.

Thank you for some different perspectives. I better just stick to the Cyclades and save Corfu for another trip. I do want to be able to experience and enjoy the islands. Maybe I could fly into Crete and visit 2 other island before visiting/flying out of Athens.

Each island hop uses up a minimum of half a day when you take into consideration checking out and in to hotels waiting for the ferry and the ferry trip itself. Minimizing the number of location changes and maximizing your time on the islands you do choose will give you a much more satisfying experience.

Crete is huge and can take weeks just to begin to discover its charms. I would respectfully suggest you spend all your time on Crete or leave it for another trip. We have gone to Crete 5 times for a minimum of 10 days each time over the past decade and we still have not been able to get to get into the east part of the island.

So it sounds like Santorini is a must see so fly there on arrival in Athens. Sign up for Aegeans web site and get notices of seat sales.
Now you have an additional 4 days for another island. I frankly have difficulty understanding why Mykonos is as expensive as Santorini when there are other islands like Naxos and Paros which are just as nice, with great beaches, interesting main towns, the same white and blue buildings but at half the price.

Take a look at what Naxos has to offer.
Naxos Town http://www.flickr.com/photos/stanbr54/sets/72157632094558042/
Trip around Naxos http://www.flickr.com/photos/stanbr54/sets/72157634605629689/

out of interest - which airline flies direct between Corfu and Mykonos?

"out of interest - which airline flies direct between Corfu and Mykonos?"

None! You have to change planes at Athens.

Just returned and traveled our butts off. Was it worth it move around all the time? Depends on who you are and how you travel. We LOVED the way our trip went. Spent the first three days in Santorini and then three on Naxos (our favorite location during 18 days of travel). We spent nine days driving through Greece and ended with three days in Athens. If you have never checked it out give Withlocals a glance (Google it) for your Athens share of the trip. Worked great for us. How much you move will really depend on you. Some people say don't do it because it burns up time, personally we treasured our interactions on the ferries just as much as the conversations in the local Tavernas.

Thanks for your reply. I'm growing more and more interested in Naxos from everyone's recommendations and stan's photos. For our 15 night trip I'm now thinking Santorini (3), Naxos (3-4), Mykonos (0-1, maybe just day trip from Naxos), Peloponnese Road Trip (3), and Athens (3-4).

I'm wondering if with 3 nights we could drive between and see Delphi, Olympia, Nafplio, Mycenae beginning and ending in Athens. I don't mind packing stuff in but B likes a little more leisurely pace.

Such a timely thread... we too are beginning to plan for September 2017.... this has been very valuable. Melissa and Brad I would love to know what you finally decide to do. Donna (Eastern Washington)

My hubby and I are also planning a Greece trip in October 2017.
I heard about the disorganized island airports of Santorini and Mykonos.
Apparently, nightmarish is the majority of comments found on Google. As in missing the flight and standing in outrageously long lines, and non-working toilets. So I hesitate to book even thou the airfare is very low and reasonable.
You may want to do more research on flying into the islands.

We are leaning to ferry trip instead.

Rowena V.

I have heard about that as well but I will probably still fly with the ferry as a back-up. A 45 min flight with the potential of something going wrong is worth the risk when the alternative is 6-8 hours. That's precious vacation time.

we flew from Mykonos to Barcelona via Athens this past late May.

The thing is.. everything went well.. but there were lines.. and a bit of chaos.. but its sort of "island time" mentaility.. just chill.. it will all work out.. and it does.

Glad and Sad to hear about Naxos popularity growing.. the locals deserve the tourist dollars.. but I would hate it to become anything like Mykonos.. yuck. It was one of the highlights of our last 30 day vacation to Europe.. we simply loved it..

Just a note about reports of airport chaos on Mykonos & Santorini .... please look at dates, and the Home Countries of those experiencing nightmares, lines, long waits etc. The problems are mainly in High Season (July - August) and most usually involve the jumbo jets and charter flights from the UK ... and maybe Germany. These flights dump 400+ people in a small airport, somtimes 2 flights at near the same time... and no wonder things go sideways! The worrier-person I believe is going in October, when flights are sparse and domestics... not direct from Europe. You will have NO problem. Also, even if going in high season, you may well be able to dodge those "mob flights" with an inquiry ahead of time.