I love the Douro valley. We spent 10 days down there during the grape harvest last year and really loved it. I regretted doing a fly drive (which had seemed like a no-brainer as it was sooo cheap) because the roads were so great and I was severely limited in the amount of wine I could haul back with me, (although I did have some shipped at vast expense). The N 222 road from Peso de Regua to Pinhao was voted the world's best road in 2015.
There is a fantastic restaurant on said road called DOC at Folgosa built out on stilts over the river.
https://www.viamichelin.com/web/Restaurant/Folgosa_do_Douro-5110_204-DOC-216528-41102We also loved the Castas e Pratos restaurant in the old railway goods sheds at Regua.
http://www.castasepratos.com/index.php?lang=ptWe stayed at a fabulous wine property called the Quinta de S. Bernado - truly wonderful.
http://www.1912winemakers.com/vineyards.htmlPedro (their winemaker) is wonderful and talented fellow. The vineyard tour followed by wine tasting was the best I've ever experienced.
Have a great trip !!