Also as was seen in France this summer for instance, one of the interesting edge cases of water cooled reactors (really any generation that needs a lot of water) is that they can get basically thermally throttled e.g. the inlet water is too warm, you might be limited on how much water you can discharge to curtail affecting local ecology.

I guess it makes sense to me that the conditions that spike electric demand also stress generation and transmission, but I do find it astonishing how universal it is, solar/wind/hydro/nuclear included.