10 day trip. How crowded will it likely be? Thinking of Dec 17-21 in Seville, 22-23rd in Granada, and 24 thru 26th in Barcelona. Things closed? Thoughts? Suggestions?
I traveled in Spain, same cities plus Madrid last year for 14 days over Christmas. The hotels were not busy at all. I was told Spanish families typically do not travel over the holidays. The streets and tourist areas were busy but not jammed. Though I pre-booked some attraction reservations, other than the Alhambra and the Sagrada Familia, none were really necessary. It's a great time of year to visit Spain!
My initial thinking would be for Christmas in Sevilla rather than Barcelona.
17-21 Barcelona
21-23 Granada
23-27 Sevilla (with a day to Córdoba)