There are methods to “harden” the power grid to GIC, and organizations such as the Department of Energy (DOE) are working on it (example: https://www.osti.gov/servlets/purl/1684647). This isn’t cheap, but is the most promising area.

It might be possible to install more isolation transformers in the existing grid. Another possible solution would be microgrids that don’t have long-haul lines, so would not be susceptible to GIC.

A nuclear EMP can do the same thing to the grid, and more, but overall seems less likely than a regularly occurring solar event we know will happen again. We just can’t predict when.

Either way, changes to the power grid will need to occur if we are to ensure it’s survival.