As funny as that is on the surface I would almost bet it would happen depending how long the outage was.
From what I’ve read, there are 2 lines of thought on Solar Flares/EMP:
The damage done results from induced voltage caused by a strong magnetic field.
The grid with all the transmission lines presents a huge surface area and will result in a catastrophic induced voltage that will destroy the grid components and anything attached to them.
Vehicles have small electronic parts. The smaller area may not be enough to induce a damaging voltage. Keep in mind that some chips are so sensitive that even static electricity can damage them so I may be wrong on this assumption.
I’m reading a series of books by A. American that involve the US gov’t using a solar flare as cover to launch a false flag EMP strike and declare martial law. It’s worth a read.
In this event, the DHS and FEMA will use food as a weapon and it will work.
Just my two cents.