Greece Itinerary Advice/Suggestions

If you stay longer in Nauplio, you might be able to go snorkeling nearby. Sorry I don't remember the details-we did this in 2008.

Our Greek friends told us not to miss Olympia or Mystras! We are so glad we saw both sites. See where the flame is lit every four years was special. The adjoining museum is excellent too.
Visit Epidavros the day after Mycenae. It is in wonderful condition.
I have never heard of tour companies for hiking the Samaria Gorge thus wonder if and why you need one? You appear to be good independent travers so this surprises me.

Can you start your trip by flying into Chania rather than Heraklion? That would save a day’s car rental & driving while jet-lagged.

That is an ambitious plan. You are trying to do too much in too short time. Crete alone needs a week to 10 days to start in depth exploration.

Just some thoughts. On arrival in Athens book a flight to Chania. It too has an airport and both Olympic and Sky express service that route. There is no point in flying to Heraklion and then driving to Chania. after a transatlantic.

I would suggest you simply take a taxi or the bus from the airport to Chania and spend the next day exploring the old town and harbour while getting over jet lag. Chania has a decent beach at Neo Chora just a 10 minute stroll from the foot of Theotokopoulo street along the waterfront. No need for a car on day 3. You won't need it. There is just too much to do in Chania.

Samaria Gorge will be a highlight. You can book an excursion from any travel agency in Chania. This hike is quite long at 16 KM down a mountainside. Many people take the day after the hike to rest sore muscles.

You could rent a car to drive to Heraklion but there are hourly inter city buses from Chania to Heraklion. Chances are the bus fare will be less than a one day car rental. You can easily get to Knossos by bus or taxi. If you have some time try to get to the archaeological museum in Heraklion.

Santorini plan is fine.
Day 8. We have used ACR Athens Car Rental several times. They are reliable. They do not have a location at the airport. They will have a person meet you at arrivals door and will take you to the car at the terminal at arrivals level. They will give you a tour of the the car, take a credit card and away you go. You return the car the same way but you will meet their rep at Departures level where you drop off the car. Good to know stuff. You have to return the car with the same amount of gas in it. There is a big gas station about 6km from the airport so fill up at the last moment. They also do a walk around the car to identify any nicks or scratches. You should probably have someone video the walk around. I totally missed a dent but my wife's video clearly showed it was there before we drove the car. Lastly they took a hold on our credit card for any charges for the deductible in case of an accident. That hold was removed within a couple of days of our returning the car.
Good call on spending that first night in Nafplio. Its lovely. Be sure to get a hotel in the old town. I can recommend hotel Agamemnon it is the only hotel with a sea view along the waterfront promenade.

On the way to Nafplio consider a stop at Corinth. You can see the canal from a bridge viewing area but you might want to find the foot path at the west side of the canal where you will find what appears to be an abandoned machine gun nest, an abandoned rail line with a bridge over the canal and on a rocky part of the path you will find the scratches in the rock where the keels of the boats were dragged across before the canal was built. That hike will take about an hour. As you continue your drive you will come to the site at Ancient Corinth. That may be of interest but if no the kids are going to love the huge fortress at Acrocorinth right beside Ancient Corinth.
You certainly will have sufficient time to visit Corinth then arrive in Nafplio mid afternoon. Nafplio old town and the Fortress guarding the city will use up all the time for that day.

Day 1/2: Please do not rent a car on arrival day since Heraklion is on your itinerary. You get very little sleep when flying over the Atlantic even if your seat declines horizontally. Sleep in Heraklion the day you arrive and settle into your hotel, shower and find a nice place for dinner. The next day visit Knossos then drive to Chania afterwards.

Since you’ve traveled extensively and have rented cars elsewhere while driving on foreign land you're aware of its challenges when driving a car, you’re not use to. Keep yourself, your family and those on the road safe so you have nothing to regret. Besides, flights get delayed and you could arrive a couple hours later.

Seajets has a ferry operating from Heraklion to Santorini and hopefully there’s one that departs later in the day so you can drive from the Samaria Gorge area, return your car and take a taxi to the port. The ferry takes 2h and arrives at Santorini’s Athinios Port that is one of the most dramatic spots on the island. I arrived at sunset and will have this view stamped in my memory for a long time.

My thought continued.

If you choose not to stop in Corinth you can get off the national road and follow the coastline to Epidaurus then finish the drive in Nafplio. Next morning visit Mycenae. You do not have sufficient time to visit Ancient Olympia. Its at least a 5 hour drive both ways. Instead consider a visit to Ancient Nemia. It is close to the National road on the way to Delphi. It is a sister city to Olympia and had games as well. The stadium is still there. The kids can run races from the 2,000 year old starting blocks. It is a great alternative to Olympia.
You can visit the museum in Delphi in the afternoon do some hiking. Next morning get tot he site at opening. You will be virtually alone for an hour or 2 before the tour bus crowds arrive. That will give you 3 or 4 hours of relative quite while you hike throughout the site. When the crowds reach you head back down and drive to Meteora. We arrived at sunset. There were no crowds around so we had time and clear views of the Monasteries. Get your photos then. Next day the tour bus crowds will arrive and block the views of the Monasteries.

Athens can be done quite nicely in 3 days. 2 will mean you have to choose carefully what are the most important sites you want to visit.
Here are some images of your trip
Chania https://www.flickr.com/photos/stanbr54/albums/72157632117917828
Santorini https://www.flickr.com/photos/stanbr54/albums/72157632154800782
Corinth Area. https://www.flickr.com/photos/stanbr54/albums/72157711755443483
Nafplio https://www.flickr.com/photos/stanbr54/albums/72157632094108982
Delphi and Meteora https://www.flickr.com/photos/stanbr54/albums/72157698930270992

Thanks all for the great advice! This is all very helpful.

For clarification, we are flying to Heraklion from Frankfurt without a connection in Athens. When I searched for flights in to Chania they were significantly more expensive than Heraklion. I'll check again, though. It would be nice to avoid the drive on arrival.

I'll see what I can find for snorkeling around Nafplio.

For Samaria Gorge it looks like we wouldn't be able to easily get back to our car at the trailhead from the trail's end, so I thought a tour would make the transportation easier.

Agree Stanbr it's an ambitious itinerary! That's why I'm thinking we skip Olympia, although, as Suki suggests it does sound nice. Still ambitious for sure.

Will check out ACR car rentals.

Will see if we can stop by Corinth.

Thanks again!

Have you booked that Frankfurt to Heraklion flight yet? If not then I would suggest that you drop all plans to go to Crete. You are doing way too much and will spend most of your time driving from one place to another and not having time to really appreciate the places you really want to see.
If that flight is not booked then you might want to consider flying direct to Santorini from Frankfurt. Skip Crete for a visit when you have a week or 2 to spend there.
That will give you 3 extra days to spread out over the mainland plan you have now. Greece is best explored slowly.

I'll check again, though. It would be nice to avoid the drive on
arrival.

If Crete is set in stone, there are other ways to get between Heraklion and Chania. Including frequent buses.

Thanks again to all for the input. I'm going to try to find ways to "streamline" the itinerary to allow us to spend more time in fewer places.

Let us know when you have formulated new plans.

The hike to the Corycian Cave hike is a good one--we went about half way, turning around at the plateau where you start losing some of the views. But that was only because we ran out of time.

This hike is also good and not too far from Delphi. https://theblogofdimi.com/trip-to-mount-helicon/ Just be warned that the the trail near the top is not great and you're pretty much picking your way through the talus--not difficult, but not a real trail either. My teenage daughter did just fine though.

Delphi is a "must see" but the sites are not big and very easy to cover, even if you linger and look at every little thing. The museum is great, but also doesn't take a lot of time. So even though we tend to take more time than most people looking at these kinds of things, and even though we didn't get to Delphi until late morning because we were driving from Meteora, we still found we had enough time to do half the Corycian Cave hike.

So personally I think that one full day in Delphi is plenty to both see the sites and the museum and do hiking.

Olympia is a "must see." If I were in your shoes, I'd take your second Delphi day and use it for Olympia.

Also, we had budgeted 1 1/2 half days for Meteora, and we found that 1/2 day was enough for us. And if we did this trip over, we'd eliminate it altogether, because it wasn't as fantastic as we were expecting and it is so far out of the way. And there is so much to do and see in the Peloponnese, especially around Napflio. BTW, I think it is totally doable to to see both Mycenate and Epidaurus in one day. Also, Tiryns is another Mycenean citadel right outside of Napflio. It is mentioned in the Illiad: Tiryns of the Mighty Walls.

You don't say when you are going. Is this a summer trip? During the winter season, the archeological sites close at 3:30 PM so keep that in mind. Check the web sites for when this ends.

Thank you Travel-Lite! This is all great info. We'll review with our itinerary.

Thanks again to everyone for the input.

We are now thinking of skipping the Meteora area and staying on the Peloponnese and adding a hike in Delphi and a hike at Louisios Gorge. That may help to keep from getting spread too thin.