Spain/Portugal/Gibraltar - Spain: driving from Madrid to San Sebastian?

Go through A- 1 via Burgos, or through Zarazoga?

Burgos.

But don't you have a reservation at the HI Ex in Zaragoza? If so, I'd suggest stopping off at the Monasterio de Piedra on the way.

Thank you. Would it be a good idea to drive N one way and coming back S the other way?

Thank you. Would it be a good idea to drive N one way and coming back S the other way?

Why not?

Via Burgos is quicker, and you have a reservation at Zaragoza.

I've only been driven through the middle of those two routes from Madrid (to Pamplona via Soria), scenery, as in most of inland Spain, was glorious.