Madrid and then Bilbao, San Sebastian and maybe Burgos..not sure, and in what order

Do you plan to rent a car or use trains/buses?

I enjoyed Burgos a lot. It's true what Rick says in his book: It's very windy there. Bundle up.

There are lots of good spots in the Basque Country, though I have no idea what sort of temperatures to expect in February. It's a great place to go in mid-summer. Near San Sebastian you have Hondarribia to the east and Zarautz, Getaria and Zumaia to the west. Bus or car is the way to travel between SS and Bilbao; the train is very scenic but also very slow.

The inland city of Vitoria-Gasteiz (south of Bilbao) has a very nice medieval district perched on a hill.

Get a jump start by hitting Valladolid on your day of arrival. There are frequent high speed services from Madrid. Then break the return journey at Burgos. Hopefully you will have 11 nights on the ground in Spain.

Day
1.. Arrive Madrid. Train to Valladolid (1)
2.. Train to Bilbao (3)
5.. Bus to San Sebastián (3)
8.. Train to Burgos (1)
9.. Train to Madrid (3)
12.. Depart Madrid

Thanks acraven and djp - I appreciate your responses.
We think we will do the following itinerary - not wanting to do too little by trying to see too much:
Arrive Madrid - train to Burgos for 2 nights
Bus to Bilbao - 2 nights in Burgos
Bus to San Sebastian - 3 nights in SS
Train to Madrid - 3 nights in Madrid
Leave Madrid for home

Any opinions on whether or not 3 nights in SS is excessive given the time of year (February)? Should we forfeit one night there for another night in Burgos or Bilbao?

I don't understand the first part of the trip. Is there a typo, perhaps?

I think if you want to do a day-trip to Bilbao, it might be better to do it from San Sebastian. It's just a bit closer than Burgos. I'd also guess that buses would be a lot more frequent from SS, but I haven't checked.

If you're thinking 2-2-3, I think it depends on where your interests fall. I much preferred Bilbao to SS. It has more museums, a larger historic district, and it is less touristy. But I'm not an extroverted bar-hopper. From the latter standpoint, San Sebastian is probably better. It also affords views of the magnificent beach.

Hi yes sorry - I made a typo. Two nights in Burgos followed by 2 nights in Bilbao, followed by 3 nights in SS then 3 nights in Madrid.
Just wondering if 2 nights is enough in Burgos and Bilbao.
Another option is 2-2-2-4 - using the extra night in Madrid. We have not been to Segovia yet so we could do that on a day trip.

Burgos has a great cathedral, a very pretty historic district, and two monasteries. The latter are on the outskirts of town (not near each other), with bus service available (though possibly not on Sundays). My favorite was the Cartuja de Miraflores; I think Rick sort of recommends the other one since it's a bit closer to the center of town. Depending on what time of day you arrive and depart, I think you can manage Burgos with two nights if you need to.

For me, Bilbao needs more time because of its size. The Casco Viejo (medieval district) is much larger than San Sebastian's historic area. Gone are the days when Bilbao was a gritty port town where travelers just wanted to see the Guggenheim.

In February, the Basque country is likely to be rainy, cool - and did I mention rainy? So, make sure there are enough indoor attractions in each place before allotting too many nights there.

For me, San Sebastian was exhausted quickly, even in good weather. It's lovely (at least if it's sunny, like when I was there in May 2017), but there's not a lot to "do." Vitoria-Gasteiz and Bilbao had many more indoor attractions (I actually saw Vitoria in the rain and had a good time anyway).

Here's my detailed trip report. Warning: the Basque country wasn't my favorite place, so that colored my experience. Many LOVE this area, so be sure to get other points of view before deciding. https://community.ricksteves.com/travel-forum/trip-reports/basque-country-trip-report-bayonne-san-sebastian-vitoria-gasteiz-and-bilbao-may-2017