I would be inclined not to go, we went to Spain three years ago to Seville and Cordoba, both fabulous and of course tourist destinations and went back to Seville the following year to meet up with friends from abroad who were having a month long stay there. Having been to both Spain and Portugal, I prefer Spain, once you get away from the Costas, but that's a personal preference, who's to say that the Portuguese might not also take a leaf out of Spain's book anyway, this dissatisfaction with mass tourism is not confined to one country. I understand the Spanish people's point of view, it's the same in many tourist destinations, here too, where locals are being priced out of available accommodation due to AirB&B. I also sympathise with them too over rowdy drunken, rowdy and generally behaviour, but they allowed the proliferation of the sort of places that attract those who go abroad for that reason only and not to embrace the culture of the country. . I don't remember seeing that demographic in France for example when I used to go there regularly which is a while ago now.
I've been several times to a couple of the islands in The Canaries in December, a good place for a winter getaway. Again, I'm not sure I'd go again now the locals have made it clear they're fed up with mass tourism. I think we have to respect their wishes, although of course it's a double edged sword I imagine, tourism = revenue, but equally it brings a multitude of problems.