Spain and Portugal for 3 weeks - summer 2020

Hi,
I like the plan but I would indeed skip Porto: travel days are mostly lost days, and I would want to spend 5 nights in Barcelona, and 9-10 in the Azores (never been, but I assume you'll want to visit more than one island, and inter Island transport eats up time).
No car in Lisbon.
Good Basque bases for a few chill days with a car are Lekeitio and Zarauz. The former is very charming, the latter has a beautiful large beach and is closer to S Sebastián and France. You then have to take train to S Sebastián from Barcelona, it takes 5.5 hours so if you're not staying IN S Sebastián proper you might want to look at flights too - car rental options are likely to be better at the airport.
Going to Lisbon requires you to drive to Bilbao Airport, which is no big deal.

I sent you a private message with information to cover the Azores part of your trip.

Balso - thank you for your response. After reading your comments, and thinking more about Porto and the itinerary, I am pretty sure we are going to skip it.

Carl - THANK YOU!

We have been to all the places that you listed, except for the Basque region.

Definitely go to Porto, love that city. Love the wonderful B&B, The In Patio Guesthouse (it is the very best ever).

We did a 7 night river cruise on the Douro that we loved. If you can't do that, take the train up the river and visit the towns on the river, some wineries and other places.

We have been to the Azores twice, while on TransAtlantic cruises. It is beautiful there, on par with Hawaii.
Not sure about the beaches. My sense was that people don't go there for the beaches. Do more research before you plan a week here.

Look at Hondarribia Spain, on the Spanish/ French border, 20 minute drive from San Sebastian. You can access both he Spanish and French Basque towns and villages from there. Medieval village combined with a fisherman's quarter. Also find maribelsguides dot com and read/print her pdfs for this area. She lives in US but travels there yearly. Very, very helpful for these areas.

While I've never been to Porto, it will be on our list whenever we go (we also went to the Rick Steves class about it). My best advice is if something looked interesting to you in the first place, don't dismiss it because one person tells you not to go (and clearly someone else on the thread loves it and so have many others that I've known that have been there). I've found that travel is really a personal thing and what you like, others may not and vice versa. At least get several opinions about it and mention why something sounds appealing to you and what your hesitation might be to question it -- others can confirm if it will deliver on that expectation or not (rather than "should I go or not?")..

We had four nights in Barcelona and it was enough time for us to see the major sites and not feel rushed to walk around, but we didn't have time for any day trips. We had three nights in San Sebastian and took a day trip (via train) over to France. I wish we would've had a car for outside the city, as it would've given us a lot more flexibility to get around, especially with the amount of time you'll have in the area.

Thank you Becky and please don't assume that one person either way sways my opinion. I have done lots of research and Porto was already on my "cut" list since I know we cannot see everything, and I do have to make sure to keep my teenagers engaged. Like many, but not all teenagers, they can only visit so many museums, see so many "cute" streets and "really cool" old buildings. Porto would be near the end of our trip and we know that they will be at the end of their rope.

Now, on to my question! If you had more than three days in San Sebastian, where else would you have gone?

Suki - thank you for the Maribels info, very very helpful.