I'm going alone too, from blueland SF C. My extended family (including an ex) is pissed. But I've put up with their grief too long. This matters. I'll look for a happy group of pedes. Cheers!
For those interested in a side trip, drive time from DC to Lancaster is 2 hours 16 min.
Hotel and flights booked. Good seats still available from SFO.
Parking at Metro in Virginia is first option. But this might fill up. And I can envision BLM blocking entry to the lots, then vandalizing cars.
Second choice. More expensive, but safer.
Pay for parking at an airport in Virginia (Dulles or Reagan). If Dulles (safer) take cab to a Silver/Orange line Metro stop, then Metro into DC. If Reagan, take Blue Line into DC.