The message was solid for maybe two dozen tries. My wife picked me up, and I left the car at work.
The following Monday I came by to clean out all my stuff and gave it a try...it started right up, but I still had it towed to the Ford Dealer.
They are reflashing the PCM, but my plan is still to return it as soon as possible and not risk getting stranded. They also want to replace the 12V battery but of course I'm not going to do that.
I got over 52,000 miles out of the thing, good enough!
So for what it's worth...at 3 years, 52K miles, the battery is down to between 15 and 15.5 (call it 15.2 kWh) useful. Assuming 19.5 originally, that's about 22% fade. Not bad, not great.
Since we are treating this current problem to software (as opposed to something actually breaking) I think it's been reliable, fun to drive, and comfortable.
2013 FFE Returned after 3 years with 52,000 miles and battery down to 15.2 kWh
2014 Volt returned with 43,000 miles
2014 Volt 26,000 miles
1967 Corvette 427
1962 Corvette 327
Awaiting a Bolt