Basque Region with San Sebastian as our Base

I think you could spend all your nights in San Sebastian, but I am not a fan of putting myself in a position of needing to make multiple day trips in the same direction (or even to the same city) while staying in one place. I'd usually prefer to split my hotel stays. I'm a public-transportation user, which definitely affects my point of view; on the other hand, dealing with parking and driving in and out of a city of any size is no piece of cake, either.

Popular potential side trips from San Sebastian that I would not choose to do that way because of travel time include the French Basque towns of Bayonne and St-Jean-de-Luz (I wasn't impressed by Biarritz), but they are accessible by train. There are some interesting-sounding French Basque villages Rick mentions in his guidebook for Spain (!), but on a short trip they'd really need a car. I haven't been to those places.

Atmospheric Hondarribia is a reasonable side trip from San Sebastian, as are Zumaia/Getaria/Zarautz. Trains will work for those, I think, but one or two of the trio might work better by bus.

I'm a big fan of Bilbao, preferring it to very touristy San Sebastian. The historic center is larger than San Sebastian's and not full of pintxo bars heaving with tourists. There's frequent bus service between San Sebastian and Bilbao; the train is scenic but much slower. For me Bilbao is more than a one-day destination, but a good bit of that time is for the Guggenheim Museum. Folks who don't like modern/contemporary art might be okay with just one day in Bilbao.

There are good side trips from Bilbao as well, Gernika, Bermeo and Lekeitio among them.

The interior capital of Vitoria-Gasteiz is another city with an atmospheric historic district, but it's about 2 hours from San Sebastian, so I don't think it's a good use of your time on this trip.

Before settling on a single or multiple places to stay you need to consider how much of your seven days you will spend simply getting to and from day trips’ sites and waiting on trains or buses. With a couple bases you could save some of that travel time.

I always get a rental car and seldom spend more than three nights in the same place. I tend to visit small villages and hamlets and with a rental car I can usually visit three villages (excluding the base location), possibly four, on a single day. With multiple stops during the day driving time between sites is seldom more than an hour.

Public transportation schedules between the smaller villages is often sporadic and many don’t have train stations.

Thanks for your replies. Regarding day trips, we would lean to organized small group or private tours. In the alternative, we would rent a car. It’s doubtful we would use public transportation.

We split our time between Bilbao and Hondarribia as bases and that was a good decision for us. We preferred Bilbao to San Sebastian, as San Sebastian was absolutely packed with tourists (we also went in October), and Bilbao was a more interesting city to our tastes, with a good mix of tourists and locals. We did day trips from Hondarribia to San Sebastian and a few towns on the French side. We rented a car and were glad not to have one in San Sebastian. The day we visited from Hondarribia we took a bus. We tend to prefer to keep our hotel switching to a minimum, but I was glad to have split the trip like this.

We love the Basque country! For seven days, maybe two in Bilbao, one or two in San Sebastian and the rest in Hondaribbia. From Hondaribbia, you can day trip to the French Basque villages and/or St. Jean de Luz. Also, take a look at stopping at Chillada Leku. We traveled by car and had no problem driving/parking anywhere.