My husband and I have traveled widely, and our love for Spain began in 2010 when we were offered use of a holiday house on Ibiza. As luck would have it, this was during the 2010 World Cups. We watched the quarter finals from a bar where staff and patrons did a little happy dance singing "yo soy espanol, espanol, espanol" with every goal or favorable turn of events. Although we were not soccer fans, who could not be drawn in by the passion? We then traveled to Barcelona, and were there for the semi-finals. We were at dinner and the wait staff were trying not to look at the TV screen until everyone, staff and patrons alike, abandoned all pretense and watched the game. When Spain won, the city went crazy, with fireworks, honking, and happy crowds shouting through the night! That night was when Spain became our country. Since then our daughter has gone to live in Barcelona, and we are there 2-3 times a year, visiting the major sights and more out of the way places like the Pyrenees, Costa Brava, and Priorat. We have considered moving to Spain for at least part of the year. Did you know it is deemed the healthiest country in the world? Our grandchild was born there, and the medical care was as good if not better than in Boston, where we're from. And in Barcelona, food is so fresh and inexpensive, it ruins you for going home to the supermarkets.
Enough personal history. Your revised itinerary looks good. Having overnight stays in Toledo and Cordoba decompresses your time in those charming cities, and I'm glad you are taking the time to do them. The Toledo cathedral is wonderful and La Mezquita is one of the most amazing places of worship you will ever see. Did you know you can visit there at night? We could not do that because we were only there for the day, but you can, and it is supposed to be magical. The Alhambra is not to be missed, although the city of Granada is worth spending time in, and it actually had a good free city tour. (make sure to tip the guide, that's their remuneration). You didn't indicate whether you are an art fan, but one interesting correlation is to see the original Las Meninas by Velasquez at the Prado and then see Picasso's version of Las Meninas at the Picasso museum in Barcelona. Also visit La Reina Sofia in Madrid, which had a great exhibit on the historical backdrop to Picasso's work, including the incomparable Guernica. Since you are interested in the Spanish Civil War, you might want also to visit Montjuic Castle in Barcelona. Most people value the castle primarily for the views but it also has a number of interesting exhibits with military and/or political topics, including a very moving exhibit on graffiti from people imprisoned in the dungeon over the years. It is the human side of history. You also will learn more about the independence movement in Catalunya. We try not to get political when we go there, but I really believe that an interest in the issues of the countries you visit makes you a traveler and not a tourist.
Anyway, I'm sure you will have a wonderful trip! And I totally understand about your concerns about your dog's health and well-being. Our 7-year old Aussie was diagnosed with cancer shortly before I was to leave for a long-awaited visit to a friend. Needless to say, the visit was postponed. Some things are important.