I think if energy storage is cheap enough and solar panel pricing continues to go down (especially with this new tech) a time where you can have 10 days of reserve and 50%+ overproduction is not that far away IMO. Small 2-3 floor apartments especially can benefit from a mini local grid, each roof + shared land is a lot of sun real-estate.

It doesn't have to be perfect a generator with ~7 days of fuel can go a really long way for any kind of low solar activity event. 7 days of fuel is roughly half the size of the generator.

At the end of the day it's math, figure exactly what is needed, if it works out then great, if not, continue waiting.