Portugal Spain Itinerary. Is 12 days enough in December end?

Hello everyone,

Im trying to figure out my itinerary to these two amazing countries. I land in Lisbon and fly out of Barcelona. Total duration 12 days. 22Dec to 2Jan.

Could anyone recommend day splits or anything of that sort? Like 4-5 days Portugal and 6-7 days Spain?

My plan of action is something like, land in Lisbon, next day head to Algarve and do sky diving and live around that area for a few days. Then head to Seville, Madrid and Barcelona and fly out to my hometown. I plan to spend NYE in Barcelona (as suggested) by internet ai.

Obviously I can't do the entire countries in 12 days, so asking you folks if there's something I need to add or maybe skip.

I'm travelling with my wife. We're both adventurers. I'm astonished by the Spanish and Portuguese history of conquest, so id happily visit museums and castles or anything that depicts their histories.

Please suggest something. I went to Switzerland some time back and I enjoyed it, but reviews here made be believe I could've done a bit more. Hence, I am asking you folks.

Cities I'd surely want to visit are Lisbon and Barcelona, as id be flying to and out from them. I don't mind taking a car, train or a flight for internal travels. Whatever is best for the time, id do it.

My preference for cities are Lisbon, Madrid, Barcelona, Seville and maybe Valencia.

Adventure activities: Sky diving and a bit of Hiking.

Thanks in advance folks. Let's hope for some good responses.