13 days in Greece w 2 college aged kids

I can only speak to Meteora and Athens.

We took a train from Athens to Meteora and took a guided tour of the area. It appeared that taking a tour was the best way to see the sites, otherwise you will have to rent a car. We returned to Athens that evening. It was a long day, but worthwhile.

With that said, I would add your second day in Meteora to Athens. I think only one day in Athens will be rushed as there is so much to see.

Are your flying from Paris to Santorini? You might be too tired to enjoy the island. I've never been so I can't speak to whether visiting Santorini for one day is worth your time.

Also be aware that ferries can be cancelled because of weather. We chose to fly from Athens to Naxos for this reason.

I'm a bit confused on your flying from Raleigh to Paris then to Athens plus the same route on return home.. Isn't there a flight from your area in the US to Athens? That would be the quickest way to Athens. Unless you can fly cheaper with your original route.

Is there a non-stop flight from Paris to Santorini? I believe you'll have to stop in Athens then make a connection to Santorini making it not worth the hassle of getting there for just a short amount of time.

You may be able to fly direct from Paris to some other island but more than likely you'll have to go through Athens then pick up a flight to your destination.

You can't fly/ferry from Milos to Nafplio. You'll have to go back to Piraeus then drive/bus to Nafplio.

You'll then need to get to Meteora which is a good distance from Nafplio.

Unless you are renting a car upon getting back to Piraeus it will be not worth the effort to get to Meteora from Nafplio.

You need to do more research especially on traveling from one location in Greece to another.

I know it can be overwhelming but I believe your schedule is not do-able.

I also agree more time is needed in Athens as there's a lot to see, not only the archeological sites but so much more.

Again research is your best tool when traveling.

Unless you need to do Santorini I would fly RDU to Athens, even if through Paris like you planned, and have the day or so in Athens and then ferry to Milos.

I'm having a really difficult time planning the route and the modes of
transport.

Here is some information about the modes of transport

Paris →-Santorini

Note that the only direct flight Paris → Santorini on Tuesday May 13th is on Transavia, (Air France - KLM low-cost airline) from Orly airport and not Roissy CDG (Orly airport is closer to Paris than CDG)

I took it several times, it's a flight of a little over 3 hours, and 1 hour time difference, you won't be tired when you arrive in Santorini.

With Transavia there are 3 fares: Basic, Plus and Max. Make sure to carefully check the baggage and cancellation policy depending on the fare you book.

Santorini → Milos

I also don't see any incompatibility to go to Milos from Santorini on Thursday May 15th. (although I'm not a fan of Milos)
You will have at least a Seajet ferry (about 2 hours of travel) and also probably a slow conventional ferry (at least 4 hours of travel)

However, as Tommy said, don't forget that to go from Milos to Nafplio you will have to go through Athens (on Monday May 19th). By ferry you will not be before late afternoon at the port of Piraeus.

So, take one of the morning flights to Athens with Olympic instead

I also think that it is too ambitious to want to go to the Meteora after Nafplio especially since you are not staying more than 2 days in Nafplio. If you go to Nafplio take the opportunity to stay there for 3 days, otherwise what's the point?

Thank you for all your responses. There is a great nonstop flight from Raleigh to Paris on Air France that is really appealing which is the reason for routing ourselves through Paris.

I was looking for a direct flight from Paris directly to a Greek Island, that is why we are thinking of Santorini. I really only want to go to Milos and possibly Sifnos as we want to explore beaches and love mountainous hiking. If there is a way to skip Santorini and just do Milos and Sifnos arriving Milos on 14 and leaving Sifnos on 20, I'd be happy to swap Sifnos for Santorini. Or is tackling 2 islands too much?
If not too much, what is the best way to do Milos and Sifnos coming from Paris?

Also, thanks for the suggestions on the mainland of Greece, I think I'll skip Meteora for this trip and just do Nafplio and Athens for the last half. Thanks in advance for all your suggestions!

Just a warning, based on awful experience (and others may echo it) -- CHAS de GAULLE Is an OK airport if you just want to get to Paris -- but it can be a hellilsh experience if you plan to change planes. Even 2 hours layover is a a hairplulling nightmare -- and Air France is notorious for short transfer-times, and then giving you NO help in making your 2nd flight. The problem its, the airport is laid out like an Octopus with far-flung "wings" ... and one must go from one-to the other on a BUS on the tarmac, which takes forever. PLUS, to do this, you go OUT of security, thtus when you finally get ot your correct area, you need to go through security. Almost no staff speaks Englilsh; an don't give a damn if you mss your connection. On one occasion we gave up, jumped, ran down a "tentacle" into the center, and on to our hallway ... we ran almost a mile, pulling luggage (and I was in my 70s) We were the last people to board the plane... and as it pulled out of the gate toward the takeoff runway I looked out of the window.. and saw the bus arriving.

IF that nonstop is irrestible be SURE to book a connecting flight with at Least 2 lhours layover -- 3 is better. Have you looked at flying to Atlanta or EWR or DC and getting a nonstop to ATHENS from any of those? Also --- YOU need to check Aegean to see if there are flights from Paris to Milos... I doubt it. Good lulck in your planning -- smart of you to start now. I've been helping 2 friend plan a Greece trip for May 3 - 24 and already its a challenge to get the accommodations I recommend both in the Cyclades isles AND Nafplio. Alas, Greece has finally been "discovered" by the whole world it seems.