A mid October week in Greece...but where?

I would drive to Nafplio, then drive to the Stemnitsa area (alternate, another coastal spot like Kardamyli). I think swimming is not super likely, but I could be wrong. The rest of your wish list is a cinch. The Bradt Guide is comprehensive.
I would not fly with only a week, but others may have suggestions of islands with direct flights in October.

I wouldn't encourage Nbpt Traveler to fly to an island. It seems she had a bad experience with a connection in Athens in 2022. :)

A week in the Peloponnese is doable with a rental car.
Also, why not more "off the beaten track", Northern Greece & the region of Central Macedonia (including Thessaloniki)

https://visit-centralmacedonia.gr/en

https://www.thessalonikitourism.gr/index.php/en/

New landscapes, new atmosphere, new people. Not bad for someone who has already traveled to a few Greek islands.

Thanks to both of you! And LOL did I ever have an issue with SkyExpress back in 2022...good grief. That was a saga. But I suspect fall 2025 is a different beast than that post-lockdown nadir of summer 2022 when it comes to flight disasters, so I am game to consider it.

Nafpoli and general area is definitely tempting for a week -- seems to offer a lot. I will be just returning from Meteora/Delphi in order to wave goodbye to my mother and sister and meet my husband, so was thinking not to go back north. It does look amazing though.

You could go to Mystras and Monemvasia in addition to Nafplio. The problem is the Peloponnese is that you are spoiled for choices.

You might look at Rick Steves tv show (video) on the Peloponnese to get ideas. He, of course, doesn't include everywhere but what he does include is still more than you can see in a week.

There is a town beach in Nafplio that we enjoyed. Pebbly so make sure you bring water shoes.

Just providing links, they're better than my words --- THE best onlilne guide to NAFPLIO (and surroundings) - http://www.visitnafplio.com/ -- comprehensive, NONcommercial, continually updated. Plus pix from photo ace & fellow Nafplio-phile "Stanbr" -- https://www.flickr.com/photos/stanbr54/albums/72177720319228274/ http://www.flickr.com/photos/stanbr54/sets/72157632094108982/

You could spend 10 days in the Argolld area and just scratch surface ... its acknowledged as the area with the most # of notable ancient sites in all of Greece... not to mention vineyards (Nemean Red: to die for).

Nafplio is a good option as it's close to Athens and is easy to get to either by bus or car rental.

Lovely Old Town and a great base to explore the Argolis Region which is not only rich in history/archeology sites but has some "undiscovered" area not visited by many tourists.

Villages like Palea Epidavrous and Nea Epidavrous, the lovely village of Fourni, the fantastic but remote Avgo (The Egg) Monastery, easy access to the pretty island of Poros and further south the pretty town of Ermioni where you can get a 35 minute ferry to Hydra for 20 euros round trip Another unique area is the Didima "Sink Hole" where you walk through a underground tunnel to the sink hole only to discover a pretty old church still in use. The unique Methana famous for its ancient volcanic landscape and little visited villages in the interior. These are just a few of the many little visited areas of the Argolis.

I also recommend the best website for Naplio and beyond:

https://visitnafplio.com/

Check out my photos/videos of the "little known" areas of the Argolis

https://tinyurl.com/39mm5ys6

Lots of great votes for Nafpoli and surrounding, and yes, I admit part of the challenge is that there is So. Much. Good stuff! I am slightly overwhelmed by planning the best possible week when there are so many good options. But if we commit to that region I can at least start narrowing down choices, thinking about 1-2 home base towns (I don't want to move locations more than twice in a week -- happier doing day trips than packing up each night). Once car rentals and lodging is set the planning can be more leisurely. I will take a look at the names suggested here and start to plot out a course!

Thanks all!

Nafplio is very central to most everything you may want to go to and experience. Lots of options for services, even a nice farmer's market. However it is geared to tourism and higher prices but if that is not an issue you'll be fine.

A great option if you want less crowds, lower prices and more of a Greek Vibe is the town of Palea Epidavrous further east and still a good base to explore.

I stayed there for 5 days and it was a joy, nice waterfront, good options for shops, markets and tavernas, nearby beach and several archeological sites right in town.

Check out this website for more on the town/area:
https://www.greecetravel.com/peloponnesos/epidavros/nea-paleo/index.html