the 2008 model Roadster -- how many of those are still running?
Nearly all? The average car is 12 years. Not because cars fail, but because new cars are registered.
A backup for something that has never happened before?
There has been a report every 10 years or so since the '60s or '70s that pointed out the most recent power outage was due to insufficient winterization.
So yes, this has happened before. Quite "often" (once a decade).
it would take a battery the size of Texas.
So the entire ERCOT exists for that one fab, and nothing else can run over it?
Or your simplification is a complete lie.
I can guess which it is.
I tell them to turn to the study of mathematics, for it is only there that they might escape the lusts of the flesh. -- Thomas Mann, "The Magic Mountain"