Cyclades

Days 1 & 10 are travel days so that's time you can't use for anything else. I would add the unclaimed day to Santorini and leave the rest as is. From Naxos you can also take a daytrip to Paros, and there is a small, frequent local shuttle ferry that will take you from Paros to Antiparos if you want to explore even further.

Since y ou are traveling with teens and Santorini does not have outstanding beaches (black volcanic grit & pebbles), I would not add the extra day to santorini... you already have 3 1/2 days there. As for Naxos, since only arrive at dinnertime and you have devoted a full day to an excursion to Mykonos/Delos, that really only leaves you 2 days on an island that is beach heaven/teen heaven. So I would add the day to Naxos .... 2 days just to vedge & enjoy beach an charming port town ... on added day, rent a car and swoop around the island ... mountains made of marble, hilltop villages, ruins, AND deserted far-out beaches. OR you could just take a ferry to Paros for the day ... OR there's a wonderful windjammer all-day fun outing to Antiparos ... BBQ, snorkel etc.

As for getting back to Athens from Naxos:

• FLYING - usually only 2 flights per day from Naxos (consider booking months and months ahead, since the planes are modern, lovely, leather seats, but only 38 pass. each. The flights are usually morning/early afternoon. So for evennig return, it's ferry.
• FERRY - the BLUE STAR at 6 pm. Book ahead at a Naxos portside agency. Reserved economy seats are comfy, leanback, to read, snack doze. But you don't have to sit indoors until you want to... snag seats on deck to enjoy sunset, then go inside for light meal, nap. (Ask for seats in SIDE compartments near window; central compartment is large like theatre, noisier). Blue Star Arrives 11:30 or midnight ... last Metro is Midnight M-Th, on Fri & Sat runs til 1 or 1:30 am.
-- A thought -- if you fly back to Athens Midday on Day 10, you'll have time to at least go up on Acropolis to Parthenon. Crowds leave by 3 or 4, and late-day light is lovely. Even if kids aren't heavy on history, when they come home, friends will ask did you go to the Acropolis, and if they say no, friends will say why? we did.

With your current itinerary, you will have two full days on Santorini and two full days on Naxos, which is not a whole lot. I wouldn't be surprised if your teenage kids will pretty much sleep through your arrival day on Santorini, given your travel schedule to get there.

I would just add day 9 to Naxos or Athens. If you really do get bored with Naxos (which I doubt), you can easily turn that into another day trip to one of the other neighboring islands like Paros or Tinos without having to relocate with all your stuff.

Also, we always like to be back in Athens a day early to be sure we catch our return flight. I've seen all plane and ferry connections from the islands being canceled due to weather conditions, and the winds can be unpredictable at all times of year.

I really appreciate all of your help!

I fixed the itinerary so it's more clear:

We are spending one week in Denmark (daughter will be finishing her year as an exchange student there). Then we head to Greece.

Greece:
Day 1 Arrive Athens 7 pm (4 hour flight from Copenhagen. 1 hour time difference)
Day 2 Athens
Day 3 Fly to Santorini ( 7 am - 7:50 am)
Day 4 Santorini
Day 5 Santorini
Day 6 Ferry to Naxos (Blue Star 3:30 pm - 5:30 pm)
Day 7 Naxos. Day ferry to Mykonos & Delos
Day 8 Naxos
Day 9 Naxos
Day 10 Naxos
Day 11 Fly to Athens (arrive Athens 8 am)
Day 12 Flight from Athens to other cities (9 am)

This will give us 2 days in Athens, 3 1/2 in Santorini, 3 in Naxos, and 1 in Mykonos/Delos. I like the idea of extra time in Naxos, with the option of various excursions. And not having to drag our stuff around to another place will be nice.

Thank you for all the help. I'm sure I'll have more questions going forward.

Why would you want to split up your time in Athens like that? That doesn't seem to make much sense to me. I'd put that all at the end.

Have you looked into direct flights (or flights with only an Athens stopover) from Copenhagen to Santorini, so you could possibly even save yourself that first night in Athens and go straight for the island?

For the day ferry to Mykonos and Delos, have a look at the local weather conditions when you arrive and look what the sea is like. If it is too choppy for you to feel comfortable, you can always move that to day 8, 9 or 10.

Ditto to exactly what Anna says! Check those direct-to-Santorini flights .... European bargain airlines may save u a lot (but beware of Ryan Air - many angry reviews). Also, when doing that day-trip to Mykonos DO check weather, and if you have a choice, take the HM Alexander vessel vs. Naxos Star. Latter is much smaller, and in long sail, less comfortable if windy.

Maybe you can have your daughter in Copenhagen look for good bargains from the package tourism section. Oftentimes, they will have direct flights where the regular airlines will not.

You're right - that doesn't make any sense. lol. I adjusted the itinerary to move Athens to the end.

We will definitely be sure to check the weather conditions, and thanks for the tip on the vessel, Janet.

Anna, what is the package tourism section? I will have my daughter look into that for sure.

Greece:
Day 1 Arrive Santorini 11:15 pm
Day 2 Santorini
Day 3 Santorini
Day 4 Santorini
Day 5 Ferry to Naxos (Blue Star 3:30 pm - 5:30 pm)
Day 6 Naxos. Day ferry to Mykonos & Delos
Day 7 Naxos
Day 8 Naxos
Day 9 Naxos
Day 10 Fly to Athens (arrive Athens 8 am)
Day 11 Athens
Day 12 Flight from Athens to other cities (9 am)

Hi Suzanne, English is - as you may guess - not my native language, so with specialized terms in particular, I may not always be using them right or know the proper terms. Also, these kinds of things may be different in each country. I was sort of assuming that Denmark would have a similar system to ours.

Possibly the term "charter airline" would have been the better one, as opposed to "scheduled flights"? Does that make more sense?

Anyway, your daughter would have to find out if that might work for you from Denmark.

Also, I have no idea how much a flight would cost in comparison if you book it from home or from Denmark. That would all be for your daughter to find out. :-)

Thanks, Anna! We will look into that for sure. The Norwegian flight from Copenhagen has a 3 hours stop in London. It would be nice to get something a bit faster. I'll have my daughter ask her host family.

Thanks again,

Suzanne

There are also some daily cruises from Naxos . Another not common destination to tourists are Koufonisia islands which have awesome blue sea water (preferable also from Greeks). Google the word Koufonisia and "enjoy" the pictures.

https://visit-cyclades.com/web/day-cruises-naxos-cruises/

Hello,

It is great that you chose to visit Greece! I am sure you'll have a great time. Greek Island Hopping is the best thing you can do, especially since you are staying in Naxos. The location is convenient to visit other islands that are close by. You might want to check out Paros, Ios and Koufonisia.

The watercolour in Koufonisia will surely astound you. Search for Italida Beach Koufonisia, Pori Beach Koufonisia, Gala beach Koufonisia... pretty exotic destinations!

Have fun!