2 week driving trip Portugal in March

Two seniors, but young at heart, are seeking a driving itinerary for two weeks in Portugal with hotel and more minor town suggestions, PLEASE!
We love staying in less frequented towns and visiting the more well-known ones. We do like comfortable, more upscale lodgings, and parking is essential with a car. Thanks!

I can't provide a whole itinerary but the less well-known towns I can suggest are Aveiro, Vila Nova de Milfontes, and Evora.

Thanks very much. I'll check out those towns.

There is an old book which tells of a similar voyage by Emily Kimbrough and her friends called Pleasure by the Busload. (They were using a VW bus for the trip - it wasn't a guided tour). I was hoping I could get a view of the book on-line so I could tell you what her itinerary was but I could only find it in hard copy. Although I did find a review of it by someone from Brown University which says that Portugal hasn't changed that much since the 1960s. https://cs.brown.edu/~sk/Personal/Books/Kimbrough-Pleasure-Busload/

I don't know whether I read this book before or after I went to Lisbon in 1964. But I didn't get much farther than the area around Lisbon. I went again with my mother in 1993 on a bus tour round trip from Madrid, but since my mother was with me, I didn't write any letters to her and so I have no record of that journey.

We decided on four days in Lisbon, pick up a rental, and head to Evora and Marvao. After that, we will go to Duoro for a few days and Porto for another three. We return via Sintra for an evening and then to the airport, for a total of fifteen days.