Thanks. I looked at a return on AA from MAD (through MIA), which prices about $200 higher than BCN but would be tolerable, and there's an IB flight that, purchased as a separate ticket, is at least cheaper than the one to BCN that morning, so that might be possible. But ticketing straight through from VLC (connecting anywhere) that day is prohibitive, and, having had a rough experience recently with IB's timeliness, I'd be reluctant to rely on them to get me there on time without at least the protection of a through ticket.
I also looked at hiring a driver, but that seemed to cost more than the roundtrip to BCN.
So the option appears to be rent a car and drive myself or not go. Would the traffic on a Monday morning before 9 am be bad?