Unless it's a holiday period, I would think that it can be done without reservations. The one reason why I would have reservations for a city like San Sebastian is that driving into the city without knowing where to go specifically can be nerve-wracking for the driver given traffic, one-way streets, etc. This can be mitigated by having a list of possible places to stay and a printed out map of where these places are located.

Ditto what Michael said, plus in SS I'd be more particular about where I stay, as it is possible to have a view, etc., whereas in a large city like BCN you have so many options. Will you be stopping anywhere in between these places, or are they set as your overnights? I'd also note that in some of the small towns, accommodation may be more seasonal. For example, I stayed in Elantxobe in May and there was only one hotel. Had I just showed up, it would have appeared boarded up for the season, but they opened a room for us since I made a reservation.

Thanks Michael and yorkshire!

Not set as our overnights - more as markers for three areas within Basque country that we'd like to prioritize. We prefer to get a very authentic experience, so if you'd recommend overnights at other smaller towns around Bilbao, SS, Hondarribia (or even the French side of the border, too), please let me know. We plan on a total of three nights in that area.

Then we plan on two nights at stops on the way back to BCN (e.g., Vitoria, Pamplona, Jaca, Huesca, Zaragoza). Preferences there? I figured we'll drive through most of these cities and stay the night in two....

THANKS!

In that case, it would be difficult for me to not stay all three nights in SS, but maybe two would be okay if you really had your heart set on staying in a smaller town as well. Getaria gets a lot of raves, but that is one town I missed. You might consider making it one of the French towns for something different.

I don't think you necessarily need reservations for this time of year. But if you have your heart set on a particular place and it's a small hotel then you may be disappointed. If you don't and want have a particular place in mind then you should be fine.

Hotels in beautiful and tiny Getaria, just west of San Sebastián: http://www.booking.com/city/es/getaria.en.html

Take a look at Torla for a stop between San Sebastián and Barcelona. Breathtakingly beautiful village at the entrance to the Ordesa National Park.
http://www.google.no/search?q=Torla&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=3wr8T_6BB4fLtAa75szjBQ&ved=0CHkQsAQ&biw=1600&bih=782
http://www.torla.es/

Just a few hundred live here, but there are several small shops, two supermarkets and some 10-12 restaurants. Had some excellent trout with cured ham in one of them some years ago.

Hotels in Torla: http://www.booking.com/city/es/torla.en.html

Just remember that parking will be a problem if you plan on spending the night in Bilbao, Donostia or Hondarribia. I'd pick one place to spend the three nights and cover everything in the Paîs Vasco from one base. You don't have allow enough time to explore the Pays Basque.

Since you will have a car, I wold look for a country home/B&B in the Urdaibai, near Gernika-Lumo. Ontxene would be my choice (http://casaruralontxene.com). Or, depending on your budget, stay at El Castillo de Arteaga, a small French Gothic castle in the village of Gautegiz-Arteaga (www.castillodearteaga.com).

There are several hotels in Pamplona with parking, so that shouldn't be a problem. You can stay in the city center with 12 hotels to choose from, or a few minutes away in the Iturrama neighborhood. We usually stay at the AC Ciudad de Pamplona in Iturrama, but the Palacio Guendulain is the best hotel in the city, if it fits your budget.

If you plan on spending the night in or around Zaragoza, then you can check out the Hotel Boston (www.hotelboston.es), Palafox hotels (5 to choose from), or one of the Hospederias de Aragón (www.hospederiasdearagon.com).

You might also be interested in downloading a copy of Maribel's Guide to the País Vasco for a little more information on the area.

If you go with Robert's suggestion, you might like to check out this place too: http://www.ellaurihotela.com/
I really wanted to stay here, but could not work it into my itinerary!

The Ellauri is interesting, if not pricey, and would be nice if you wanted to stay out in the country, but not a great location for exploring the rest of the País Vasco with only three days to spare.

Whatever it costs to park, I would not put myself out of walking reach of the tapas scene and restaurants in any place I was going in the Basque country. If you put yourself out of walking reach for ease of parking, you will probably end up paying taxi fares anyway, unless you are going to deprive yourself of just about the only reason to go to that area in winter.

As always, you need to check if there are any big celebrations, arts festivals or trade fairs during your travel dates that could book up hotels. One time, I drove through a part of Italy in Spring that tourists almost never go to, and I headed for an old resort area that I knew was overloaded with huge 19th c. hotels that sit empty most of the year. Sure enough, it was the Miss Italia contest that weekend. I found a room, but it was a close call.

But I recently traveled through Galicia in the first weeks of September, with gorgeous weather, and I booked all my hotels and paradors less than 24 hours in advance using booking.com. The only exception was the airport hotel I booked for the night before my departure.

Thanks everyone! Quick follow up question - goldenautumn, great point about staying walking dist to the tapas scene -- where is this concentrated, geographically, in SS?