So is the Madrid Barajas Airport simply an entry/exit point, and are you heading directly for Andalusia once you land, not spending time in Madrid?
If so, we used the Rick Steves guidebook for a lot of our Andalusia trip. We rented a car for part of it, but didn’t have one in Granada. Driving to Seville, the car was a liability, as we dodged swarms of young people on motorbikes and scooters, unloaded our luggage at our hotel in the old town, then parked it in an expensive lot some distance way, until we were ready to leave.
There was a strike during our stay, and having our own wheels didn’t limit our being able to drive and get places, although it also caused a lot of sights to be closed. You can prepare and plan, but sometimes surprises come up, so flexibility and some optimism can help get you through rough spots.
The 2 biggies are Granada and Seville. Rick didn’t even cover Cordoba in his book when we were there, but it has a prominent chapter in his book now. As you may have discovered, Rick’s “Backdoor” town in southern Spain is Ronda, a great place to visit. We didn’t actually stay there during our trip, only visited one day, but it might be a convenient place from which to base yourselves if you’re looking for a third place.
In Granada, be sure to treat yourselves to a soak at one of the Hammam Arab baths, and get a massage there, too. You’ll appreciate what it must’ve been like when the baths at The Alhambra palace were operating centuries ago!