Porto to Lisbon via Coimbra and Obidos--is this feasible?

Even stopping just in Coimbrã is going to be a long day. The driving times always (for me, anyway) end up being longer than I estimated. I would suggest just stopping in Coimbrã.

I thought Obidos was way too touristy and crowded for what you see there. I didn't see anything in the tourist shops (that's all there was) that I didn't see in other places. Coimbra is a pretty town and the old university is beautiful. The "main drag" has some nice shops and several places for good pastries and drinks. I loved both Batalha and Alcobaca (I love Gothic architecture). They are different, Alcobaca is austere Gothic, Batalha is very ornate Gothic. There were a couple of nice souvenir shops and a good bakery near the entrance to Batalha.

I also suggest you skip Obidos. Not worth spending an hour there seeing a bunch of tourist shops and crowds. You could just do a drive by, as part of your day journey, to see the walled city from a distance. That view is pretty impressive.
We spent two nights in Coimbra and enjoyed it very much. Pleasant city and very beautiful University. You might be able to stop in Alcobaca or Bahtala for 90 minutes. Pick whichever is most convenient stop along your route to Lisbon. Most likely easier bus parking in either of those than in Obidos.

thank you Chani and KFog!
I have pretty much decided that with all the restorations, more cobbled hills, and crowds it's better to skip Obidos and instead head to.....Monastery. The problem is that I've been watching everything available on both Batalha and Alcobaca on YouTube...and .. I should not have! They seriously both look so amazing and so different. The over the top amazingly beautiful Batalha. For Alcobaca I might be a bit strange, but on par with the tombs of Pedro and Ines, I am super into seeing the kitchen with its ingenious water supply system.

So what i am trying to say... is that now I cannot seem to give up on either of these... :))

Hi from Wisconsin,
Getting to either monastery can be slow driving. As much as I hate to recommend using the big roads, where you might as well be in the US, getting to these two and away from them can be a task involving much time.

Obidos, stayed there four or five days. We used it as a base. In March when we visited the tourist numbers were very light. But with really only one street through the long walled city, it could easily become crowded. One hour to walk that street. Guess you will be jogging and not stopping to walk the city wall or enter shops.

wayne iNWI

Batalha is the more impressively ornate, so it's probably better for your group (plus the shops and cafes are a lot nicer than in Alcobaca. Your problem is my most frequent one - too many wonderful places, too little time.