Hi Rob
We have been to Portugal twice with our van - 2007 and 2008 between April and June. We stayed at Turiscampo near Lagos for about three weeks each time (number 581 in Camping Cheque book). This is an excellent site - one of our favourites of all the places we have been - and we are thinking about going there again next year.
We have stayed at Ruta de la Plata at Salamanca (no. 540 in Camping Cheque book) which is fine for a couple of nights, and Salamanca is well worth a look around. The site is about 250 miles from the ferry, on good dual carriageways.
From Salamanca the new road south to Seville (financed by the EU!) is excellent. We crossed the border at Badajoz and stayed at the Orbitur site at Evora in Portugal. Again, fine for a few nights, and Evora is a very nice historic town to look around.
From Evora to Lagos is an easy journey - the Lisbon to Algarve motorway is very expensive but the alternative roads are very good.
I don't remember spending any money on motorway tolls on this route - if we did, they were not significant.
We have also stayed at Camping las Canadas, near Bejar in Spain (south of Salamancar - no. 539 in Camping Cheque book). We didn't like it in June because we were the only tourer amongst all the Spanish statics - very noisy families enjoying themselves! But there is a very nice restaurant and bar at reasonable prices.
If you want to see more of Portugal you can go from Salamanca across the border to Guarda and then down to Lisbon. This is motorway standard and free until you meet up with the Porto/Lisbon motorway, but adds about 50 miles to the journey to the Algarve. We did this in 2007 and stayed at the municipal site in Monsanto park Lisbon - nice site with cheap bus or taxi transport to the city centre. You would have to check if it is open in November.
Hope at least some of this is useful to you
Keith