In the long run we can look forward to more exotic technologies like grid scale battery stations and small nuclear reactors. But in the short run the objective

In the long run we can look forward to more exotic technologies like grid scale battery stations and small nuclear reactors. But in the short run the objective should be to use renewables when possible and fossil fuel only when necessary. Power companies don't need to tear down oil and gas generators right away, they just need to scale back their use as they rely more on renewables. You mention two mitigations, expanding the geographic region and overprovisioning. Both of these raise the cost of transition, but not prohibitively.