I was in Andalucía last April for about a month, beginning on April 10. I agree with everything Carlos said but would like to emphasize that you really should allow extra time in the cities you'll be visiting during Holy Week because of four factors:
- You'll want to spend at least a bit of time observing the processions.
- The processions will sometimes significantly slow your progress from sight to sight; for me Seville was where this was the biggest issue.
- Some sights will have additional closing days or will open late or close early on one or more days, narrowing your sightseeing window. You may need to visit the same part of a city two or three times because of the odd schedules (happened to me in Cordoba), which makes for less efficient sightseeing.
- Although not mandatory, it will be a good idea to go by the tourist office in each city you visit during Holy Week to pick up the list of opening hours of all the sights. That will allow you to plan your time with more precision, but it may take a bit of time to get to the T.O. I suspect you won't be able to find that information on the internet before you leave home, though it would be worth trying to do so. I have a feeling those schedules don't get finalized until right before Holy Week.
Last year was my first visit to Andalucía in decades, so I have no idea whether any sights were more crowded than usual. The only ones for which pre-purchased tickets seemed necessary were the Alhambra, the Alcazar in Seville and the Cathedral in Seville. As you will see if you search earlier threads on this forum, buying advance tickets for those sights is always recommended. The Allhambra is capacity-controlled and sells out--at least for daytime visits--just about every day, so I don't think it will be more crowded than usual during Holy Week. I suppose the number of nighttime visitors might be higher than usual.
There is crowding along the processional routes and crossing them can be very difficult, especially in Seville, but I wouldn't call it "chaotic". If you have someone in your group who will freak out if he/she gets separated from the others, that person may need a bit of extra attention, because I think it might happen at some point if you're moving around as a group of six (again, probably in Seville).
So my recommendation is definitely to go, but don't try to cram in too many cities. I would spend all the time in Andalucía, not tack on Portugal, which deserves its own trip. My suggestion for rock-bottom minimum times in the three key cities:
Seville: 4 nights
Cordoba: 2 nights
Granada: 3 nights*
- I like 3 nights even outside Holy Week, but will grant that if you go to Granada before Holy Week and are really pressed for time, I guess I'd recommend cutting a night from Granada rather than from Seville or Cordoba. It's likely to be a bit cooler in Granada, too, due to altitude.
I'd suggest 5 nights in Seville and 3 in Cordoba if possible, but you'll have to weigh those allocations against your desire to see Cadiz and/or Jerez, Ronda, the white villages, Malaga and Ubeda/Baeza. I think Ubeda/Baeza are likely to be cooler than the other places I've listed at the time you're traveling. I had a couple of cold mornings there (one of them also very wet) at the beginning of my trip (April 10 and 11).