What about Holiday Inn Express Madrid-San Sebastian d/l Reyes? It markets itself as an airport accessible hotel, but probably there is no shuttle meaning an expensive taxi ride. A one day car rental for the overnight is coming in at around EUR33 at rentalcars.com, cheaper than two taxis.

Just studied this hotel, won't bother, it's too much trouble. Both the Bernabeu and Alacalá are too dear on the dates I need to stay, so I will go to the Crowne Plaza. On my return trip through Madrid I will stay at one of the two mentioned above.

Actually, looking at it, Bernabeu seems a lot easier to access with the metro. Unless I can get close to the Alcalá hotel by using the 200 bus. I know that it sweeps past the top part of Calle Alcalá, and all sorts of airline staff were waiting to catch it at 5 o'clock in the morning when I went back to the airport. One of them managed to send me to totally the wrong terminal to check in for my AirEuropa flight!