russ_in_LA This sounds like a wonderful trip, only because we are planning a very similar itinerary 😄
We had it planned for Sept 2020, canceled, thought to move it to Sept 2021, but now I'm thinking we'll move it to March-April 2022. We have about the same length of time as you, but we're skipping Evora and Monsaraz. We have the same 4 full days in Lisbon and like you, decided to be based in Obidos for a couple of days. I hear all the things against it, but we'll only be there in the morning and evening, so hopefully not impacted by too many tourists. Plus, it's a photographer's dream they say, so I want to see it and have time for it. We also plan to stay in Sintra for a couple of nights, and decided on a change from the 2020 itinerary: instead of Douro Valley (although we might have time for a day trip from Porto) we'll visit Algarve for a few days. Those rocks look incredible, don't they?
I know this does not tell you anything new, maybe just re-assurance that you're not the only one with this plan. Have a great trip, I hope you'll get there this year!

We stayed overnight in Obidos 2 years back; it is as others have said, very busy during the day, and very pretty at night when others have left. If there are other day trips you want to take in the area, then it makes sense.

We were there just before the chocolate festival. We not real brightly thought it would be neat to walk the castle walls one night. Visibility was OK...until we came to all the lighting cables they had strung in preparation for the festival. I got a case of the heebie-geebies, it's about a 15-20' fall to coblestone where we were. Quickly found the stairs and dismounted.

Have a great trip, been twice with a third visit canceled last November, hoping that a November 21 visit holds up. AA has already canceled our points flight once. Tons of great advice in this thread, thanks to all, bookmarked.

Thanks everyone for the replies and advice. thursdaysd, your photos look wonderful! I’ll let you know how it goes once we arrive.