I (29F) will be traveling to Portugal during the latter half of December. I'm flying into Lisbon and will have a bunch of solo free days before meeting up with a friend. I'm saving most of the Lisbon activities/day trips (like Sintra) for when we meet up, so I'm looking for advice on where to go solo in the meantime. I've done some research and am so overwhelmed with how many incredible things there are to do in Portugal, so I'm turning to y'all for some advice!
If it helps, I'm an art historian who adores art, architecture, and museums. I also love beautiful natural scenery and just wandering around towns. I'm a vegetarian and am aware that I might have some trouble finding good food in smaller towns (though I'm willing to be a temporary pescatarian if needed). I'm thinking of sticking to the central and northern areas. I'm aware that it won't be warm and might be very rainy, though I'm not too worried since I'm coming from an area with much, much worse weather. I'm definitely planning to pack for rainy weather. Given that it's not tourist season, if any of these destinations aren't worth visiting at this time, please let me know!
Potential itinerary:
Day 1: Arrive in Lisbon in the early morning. Rest/explore.
Day 2: Rent a car and drive to Coimbra. Maybe stop in Tomar for lunch/a bit of exploring
Day 3: Coimbra
Day 4: Drive to the Douro Valley. Maybe stop in Aveiro for lunch/a bit of exploring
Day 5: Douro Valley
Day 6: Drive to Ponte de Lima
Day 7: Ponte de Lima
Day 8: Drive to Porto and return car. Maybe stop in Braga or Guimaraes on the way and then do the other as a day trip
Day 9: Porto
Day 10: Porto
Day 11: Train to Lisbon.
If this seems crazy ambitious, I'd love some advice on what to cut.
Thanks for any help!