I'd like to thank in particular Walt Fricke for helpful posts and Dave Kost for offering another place to leave the car if I needed it.
After an uneventful drive from Davis, WV back to Pittsburgh and booking myself a one-way on Southwest for Sunday evening in case I needed it, I ultimately decided to drive it home. Leaving the car would have enforced a return for Grand Prix weekend
(which I'll likely do anyway) and freed up a garage space at home for 4-5 weeks to allow me to do some maintenance on my normal cars without kicking something out of the garage, but in the end I concluded the only risk of driving it home was FOD in the cylinder and that that risk was very low, below my threshold for accepting it.
There was no way anything was getting threaded in that plug hole - yes, all 12 threads are stripped. I may not be able to see it, but I can feel it. The drive home was merely loud. I kept the revs down but otherwise drove normally.
In a perfect world I dream of being able to TimeSert (or whatever) the plug hole without taking the head off, but I'm not willing to bet on the odds that cutting lube will hold all of the shavings from cutting new threads and keep them out of the cylinder. So it looks like once the engine is out, the head's coming off and I'll be asking new questions
David