Initial stages of planning - trying to nail down high level plan. Please see draft itinerary below. I would love comments - negative and positive. Other things to know

• Two adults and a 17 year old
• Love hiking - Picos de Europa big deal for us
• Want the charming seaside town experience
• Want to see Donostia
• Interested in history

Day 1 Fly into Madrid in the morning Rent a car and drive to Donostia-San Sebastian
Day 2 San Sebastian
Day 3 Bilbao
Day 4 Bilbao
Day 5 Santander
Day 6 Santander Day trip - Santillana del Mar
Day 7 Ribadesella Day trip - Poncebos/Cain - Cares Trail or Ruta del Cares
Day 8 Ribadesella Day trip - Cangas de Onís
Day 9 Ribadesella Day trip - Llanes
Day 10 Oviedo
Day 11 Oviedo Day trip - Gjion
Day 12 Drive back to Madrid

Yes - I do think that is one too many hotel stops - too much packing and unpacking. But, I don't know what to cut?

Thanks!!!

I should have added - this trip is late June/early July

It's a lovely area!

First, if you will be crossing multiple time zones, please do not plan on renting a car until you have been in Spain for a least a day -- more than 24 hours. Driving after crossing multiple time zones is just as dangerous to yourself -- and anyone else on the road -- as driving drunk, and there is absolutely nothing -- NOTHING! -- you can do to reduce the risk. Not sleeping on the plane, not drinking caffeine, nothing.

You can fly into Donostia rather than into Madrid (perhaps through Madrid, but with more options for your stop en route). Or you can take a train from Madrid. You can identify your options with rome2rio.com

Given that hiking in the Picos de Europa is a priority, I would have expected to see you spend time in Potes or Congis de Onis -- but maybe day trips will work for you.

To limit your one night stays, consider staying in EITHER Bilbao OR Donostia, rather than both. If you insist on flying out of Madrid, you'll probably need be there the night before your flight, so you're stuck with that one-nighter. I'd be looking for a flight out of Oviedo, but that's just me. (Search flights using a multi-city option, aka open jaw, specifying that you want to start in Bilbao / San Sebastian and end in Oviedo. See what the flight search engines come up with!)

If you haven't already seen it, you might find some useful information in my trip report:
Four Awesome Weeks in the North of Spain and Catalunya

Hope that helps!

Day 1 Fly into Madrid in the morning Rent a car and drive to Donostia-San Sebastian
Day 2 San Sebastian
Day 3 Bilbao
Day 4 Bilbao (side trips to the Hanging Bridge-Puente Bizkaia, San Juan de Gaztelugatxe (GOT), Mundaka, Bermeo, Gernika...). Lots of hiking in the area too
Day 5 Santander (one day is enough)
Day 6 Santander Day trip - Santillana del Mar (add Comillas to this trip, Santillana is worth two hours)