At that point, that grid connection will be the least of anyone's worries. The storm in Quebec in... 1990? Ish. tripped breakers, and shut things down for like a day.

A storm on the scale youre talking about I am pretty sure would wipe out satellites (maybe even take them down due to atmospheric drag?), impact cables other than power like copper laid for internet and phone, etc. Grid-connected power or not you'd be severely impacted and potentially at risk.