You have all been very helpful, and I have another question!!

Is it worth the 4 hour drive from the Algarve to Marvao, and if so, is two nights too many? Any place to stop on the way to Mavao?
We will be driving back to Lisbon from there, another 4 hours. Same question!

Again, this is our itinerary:

Lisbon. 2 nights
Obido. 2 nights
Porto 3 nights
Lamego. 2 nights
Belmonte. 2 nights
Evora. 2 nights
Lisbon. , airport hotel , dropping friends off, spending the night, getting another car in the morning