I had a similar discussion in the low 1990s at a large electronic manufacturer that had a pair of Unisys mainframes, one in São Paulo and another in Manaus, in the Amazon region communicating over a satellite link (two large 3m dishes on both places). There was one question of what happens if both fail at the same time, and I pointed that anything that takes out São Paulo and Manaus at the same time is a civilisation ending event, and we shouldn’t worry too much about that.

Anyway, we had a load shedding agreement with a large bank across the street from São Paulo and we could switch over to their Unisys mainframe in a matter of minutes, and vice versa.

You also need to understand whether the generator backup actually runs everything. Where I work it doesn't. Only "essential" systems get backup power.

And if the data center is more than about 5 years old it almost certainly was not planned with adequate backup power to run racks of GPUs.

That's probably already true for 7 days or less