I think Doc should find out what he likes to see and do besides riding his bike and get on the juice by 11am.
Doing a bit of self discovery and being interested in some subjects, will in turn allow him do his research of the area based on his interest.
Some people like architecture, others have great interest in religious monuments and temples, some love history, others interested in visiting museums, and buying the touristy tat, but I sense that majority of UK riders go to Spain for riding the great and often empty roads, then indulging in some cheap plonk and grub.
Knowing what one wants from the trip, will bring a greater experience overall.
I personally love great views (called miradors in Spain) that keep popping up along the route and stopping there for 10-15 minutes at the time, just to watch the nature around me, a stop in the forest for a picnic, a day of the bike and going for a wonder around an old town, naturally I love the pleasure I get from riding the roads and good food*.
I quite often find that I come back from the trips, feeling like I’ve been places but seen none of them. The more bike trips I take, the more I realise, that perhaps 150 miles in a day has actually more value compared to say 200-250 mile. Because you get more time to stop and absorb your surroundings and actually experience the trip properly, feel like you have been somewhere. A planned (into itinerary) day of the bike every 3 days or so is also welcome, to stretch your legs and to see a bigger town that might have specific importance or interest for me.
* as I am a long term Vegetarian, eating on the trips, that is one area that I tend to struggle with in France and even more so in Spain.