In general, this coast is quite exposed to
winter storms and so I would plan to
lift the
boat and store it out of the
water for the winter and combine this with
maintenance work.
One of the best facilities for winter
repair work is in Lagos,
Portugal. In
Spain, here is more protection up one of the rias (long sea inlet). For example, Vigo Spain is better protected because it is at the end of a ria. You could try Real Club Nautico de Vigo if you want to leave the
boat in the
water. I have left my boat there for a few weeks.
La Coruña is the principal port on the Spanish coast but Marina Coruña is not very well protected from swell. I have left my boat at Marina Sada (near La Coruña), out of the water, for one winter but I don't think there is sufficient
depth or lifting capacity to handle a 68ft boat.
Overall, of the places where I have direct experience, I think Vigo or Lagos are good options.