Depends on your budget!
There is a Formule 1 on the South Side of Valladolid on the old Madrid Road.
In Salamanca, there is an Ibis near the city centre.
Both are in the town and require one to come of the motorway.
The Valladolid one has outside parking while the IBIS in Salamanca has paid underground parking.
http://www.accorhotels.com/gb/hotel-3693-formule-1-valladolid/index.shtml
and
http://www.accorhotels.com/gb/hotel-3672-ibis-salamanca/index.shtml
I did the run Lagos (Algarve), Seville, Salamanca, Valladolid, Bilbao, Bordeaux, Rennes, Carhaix (Britanny), in May this year. My first overnight stop was at the Formule 1 in Valladolid. Its very basic but functional.
Stayed at the Salamanca IBIS a couple of years ago and it was v. respectable. BTW, Salamaca merits a couple of hours wander if you are at all interested in History. Some lovely architecture.
BTW, forgot to mention that it will be cheaper from the point of view of tolls and fuel to run Salamanca, Caceres, Merida, Seville, Huelva, Albufeira. It is motorway all the, apart from about 20km south of Salamanca which is currently being upgraded.
