Hi Michele! That's amazing - you're going to have a great time and I'm really jealous. Enjoy every moment and take the time to explore to your heart's content!

That trip was a godsend!
So I got the vermouth recommendation from another friend who spent time in Barcelona, and everywhere I went, it was proven correct. Regular people drank vermouth everywhere, all the time; it was the most easily available drink in corner stores, grocery stores, and delis. Every market stall with a bar seemed to feature one. I never looked into the provenance of Jerez, but I'm going to assume it's more native to the Jerez region, where sherry is a lot more common.
I didn't drink any white wine there! Just vermouth on ice, or even straight (if it is very good vermouth, it can be had straight). And honestly, it was the best decision I could have made, both for the pocket and for my feeling like a local 🙂

I don't like cocktails (I don't like sweet drinks in general) but I'm sure I'll find plenty of dry white wine there. I have friends in Barcelona but am not close enough that I'd think of staying with them; however they should have some good ideas.