Crete for 10 days - a good idea?

Crete is an excellent choice to visit. You could easily just do Crete and then Athens at the end of the trip and you would barely see much of Crete. I am not suggesting you change your plans as you have chosen your destinations pretty well.
You could drop a night night in Santorini and another night in Athens and add that time to Crete.both Santorini and Athens highlights can be experienced in 3 nights each.
I would suggest that you consider spending your time in Chania Crete. It has an airport so is easy to get to. Find a hotel in Chania old town. You can imagine what it was like in the 14th century. There are a number of excursions of west Crete from Chania. Any travel agent can book excursions for you. We discovered Wanderlust tours on our May 2024 visit and had 3 amazing different tours with them to many of Cretes highlights. We no longer rent a car to explore ourselves so a tour keeps us active.
Some images from Crete.
Chania 2024 https://www.flickr.com/photos/stanbr54/albums/72177720318408008/
Wanderlust tours Chania https://www.flickr.com/photos/stanbr54/albums/72177720318394812
Gramovossia,Balos and Elafonissi https://www.flickr.com/photos/stanbr54/albums/72157698932695812

10 days in Crete will give you a great introduction to Crete, where there is so much to see and do. Aside from the trip to Hydra, Rick’s tour of Greece does not cover any of the Islands, hence no guidebooks. My preferred guide to Crete is the Rough Guide, gives you lots of information on the many things to do in Crete as well as a brief but comprehensive history of the Island.

Chania is a charming old city with a stunning waterfront. Love wandering through the old town, lots of interesting buildings including excavated ruins from the Mycenean and Minoan periods. I have not been for some years but understand there is now a new archaeological museum.

A visit to the Palace of Knossos is a must do and as Stan said, tours are available from Chana that probably include the city of Heraklion to visit the museum there which contains artifacts from Knossos and other major sites on the island.

There are some great beaches or you can go hiking the various gorges. Also look at the central and eastern end of the Island. The towns in. Central Crete tend to be tourist resorts but there are some beautiful spots, especially around Elouda, where a visit to the island of Spinalonga with its massive Venetian fortress is interesting.

I never made it to the southern coast of the Island; it’s a lot less developed than the north coast.

Aside from the Rough Guide look for also Lonely Planet. Eyewitness do a nice small Top 10 Crete which is handy to carry with you, not so much for planning.

Crete is fabulous. I have provided a link to my trip report where we spent 11 nights on Crete and would have liked two more. So very easy to spend 10days. More is better and I totally agree with Stanbr’s suggestions on allocation of time. I also would consider moving one night from Athens and one night from Santorini to Crete.

Crete is one of those places we keep talking about going back to. The southwest coast in particular stole our hearts.

https://community.ricksteves.com/travel-forum/trip-reports/report-on-trip-to-crete-delphi-and-meteora

Crete is great. Just because RS has not written about it should not concern you. In fact, the less he writes about anywhere the less crowded it may be.

10 days in Crete is amazing. We went for a week last year with our similarly aged children during April and we all loved it.

I would, however, reconsider Santorini. We did that and we were totally bored after one day. There are really no good beaches. It is a honeymoon place, not a family place. I suggest going to Naxos and maybe making a day trip to Santorini at some point.

Agree with all these other posts. If you’ve got a car and especially stay in a couple of different parts in the island, it would be very easy to fill 10 days there and the hospitality is out of this world.

Thank you everyone! I'm not sure how to reply to individual posts yet.
I'm feeling much better about 10 days on Crete.
I think we'll take Santorini off the schedule and add in Naxos.
How long on Naxos would be good? 4 or 5 nights?
Is Hydra a must see for a day trip out of Athens (if we stay in Athens 4 nights)?
Thanks!

We stayed four nights on Naxos and really wished we had stayed five. So I would vote for five.

If you are already going to two islands, I would not go to Hydra. You could stop at Delphi on way back from Nafplio and spend one night there, if have extra night. Or add one night from Athens to Crete. You can always use another night on Crete, as it is a large island.

Yes adding a night to Naxos is a good decision. There are excursion boats from Naxos that go to Santorini. Perhaps you could take that excursion rather than staying in Santorini. Its a lot less expensive option.