We are planning to be in Coimbra or Aveiro before returning to Madrid to fly home. So far it appears that all the trains from Portugal are long long long and overnight rides! Not particularly cheap either. Driving is not in the cards at all. Flying appears possible from Oporto and/or Lisboa. Any experience with these that you can share?
I'd prefer not to fly on "puddle jumpers"!
Check out flight options on skyscanner.com. Rest assured any aircraft you would fly on these routes will be mid-size jets, not puddle jumpers. Ryanair for instance, which has a lot of flights from Porto to Madrid, only flies the Boeing 737. Portugal and Spain are not the poor, backward countries they were fifty or a hundred years ago.
Ryanair has Oporto/Madrid flights for $52.