So now I'm back to my confirmed reservation, which was the scheduled 8:05 departure that currently shows a planned ETD of 10:25 PM, and arrival OAK 12:08 AM. This is too late to make it to BART -- BART gates close at midnight.
But I do have an idea: There is an 8:05 PM departure for San Francisco that is currently showing on time. If I can get on that flight, which arrives SFO 9:54 PM, I can take BART home. I might even be able to take BART to Oakland Coliseum, take the bus to the airport, retrieve my luggage, take the bus back to BART, and go home from there; however, the more likely scenario has me going home and then driving to OAK tomorrow sometime to rescue my luggage. This would be annoying -- I'd be without my CPAP tonight, for instance -- but not catastrophic.
It's likely that my luggage went on ahead of me, as this usually is what happens in these standby situations, I've found. This at least means that I shouldn't have to wait long to get to my luggage when I eventually do get to Oakland.
If this scheme doesn't work out, I might be better off if they need to bump people here at Portland and just stay the night here and work something out for work tomorrow. OTOH, I absent-mindedly packed my blood pressure medication in the checked luggage, so even though I remembered to put an extra dose in my travel kit, I don't have the travel kit with me. It won't kill me, but it's not a good thing.
Update, 18:25: I'm now on standby for the 8:05 flight, and the agent confirmed that my luggage went on without me. (The "V/S" on my luggage claim ticket means "Voluntary Separation" and means I agreed they could do this, which I did.) While I won't know for another hour whether I'll get a seat, the agent seemed cheerful about it, saying that there were nine seats open on the flight.