2021 Trip - Can we tour Spain and Portugal coastal areas in 2 weeks?

If you take a peak at a map of the Iberian Peninsula, Barcelona is in the north east, Valencia is in the east, Granada in the south, Sevilla in the south west, and Lisboa is in the west so, that's wayyyy too far apart, even without combining with Portugal. You should also know that there are not many ground connections between Portugal and Spain, if you rent a car you will also incur a big fine if you pickup in Spain drop off in Portugal.

I'd strongly recommend you do not try to combine the two countries with only two weeks, outside looking in it may seem like a good idea, but its a lot more difficult than one would think, especially with limited time. There are many different Costas all over Spain and Portugal, at most I'd pick one or two, like the Costa Brava and Costa Dorada (both in the north east).

Agreed, it seems like you would like to leave for Spain and Portugal in the next two weeks, which is certainly not advisable 😉

No. Spain is a large country. Choose one country. Two weeks we’ll for Portugal. Or choose a few regions in Spain.Not both countries. We did both in six weeks but in Spain we only did five provinces.

Way too much for two weeks. Pick one country and go.

Also, why ignore Madrid (and neighboring Toledo and Segovia)?

Yes, too much in 2 weeks ... my suggestion (FWIW) would be to fly into Lisbon and spend a week there and it's surrounding areas (day trips to Sintra and Evora), then drive down to the Algarve for another week, then fly back out of Lisbon ... did that (plus going up north to Porta and the Duoro river area) for 2+ weeks last Labor Day ... I'd go back in a heartbeat ... if you like seafood, you'll be in heaven ... sardines cooking on an open grill outdoors, I can smell the aroma now ...

Way too much to do and see in 2 weeks. Agree Portugal is manageable in 2 weeks and there is a lot of variety. We loved it all. Fall is a good time.
Or be very selective and spend the 2 weeks in Spain and scratch the surface. There is so much to see and do. We love it too. If you MUST go to both countries then for example you could spend most of it in Portugal , flying into Lisbon, there, and then fly from Lisbon or Porto to say Barcelona , spend a few days and return home from there(Or vice versa ) Not ideal ,as you waste a day in transit to Barcelona and reorientation .
I wouldn't do it now as I have fewer time constraints than other times, but I understand the impulse , having done similar things in the past. What I have learned over the years is: You want to see everything. You can never see it all on one trip so slower quality time seems to be an overall better experience.

Depends on how many nights you plan in each location. It's 1000ish miles to drive from Barcelona through the places you want to visit to Lisbon. Don't want to spend too much time in the car do you? I've done several European driving adventures and would probably drop Barcelona and Valencia. Maybe fly to/from Seville and drive different loops to avoid the rental car drop off fee.