And not many people out of bed.......Some newplots.
This morning at midnight, 0000 hours, at home I obtained the following plot with virtually no non-linear loads on in the house.
The blue curve is the full AC line voltage. There appears to be less distortion than in previous plots. i did not capture an expand plot of the peak. At this time of night on a Sunday night I would expect much of Detroit industry has not yet started up.