[aerohead]

Since light travels faster than ions, and since there are solar observatories, around the world, continuously observing the Sun, plus satellites surrounding the Sun, if and when a CME event takes place, and NASA calculates that it's path will intersect that of Earth's magnetosphere, utilities around the planet will have a matter of minutes warning, to 'open-circuit' there infrastructure, until the threat passes.
Even the 'earth-ground' protection of transformers will be interrupted, to prevent telluric currents traveling from the ground, 'upwards' into the transformers from 'below.'
There won't be any 'surprises,' and less risk of service interruptions than ever before.
Even Earth-orbiting satellites can be 'powered down' temporarily in order to protect their electronics from static charges penetrating the magnetosheath.
On-site power generators and grid-scale batteries/ inverters can handle emergency loads until the grid comes back up.
Presently, hotels in Tokyo, Japan can 'run' off the ' micro-grid' bi-directional electric flow from Nissan Leafs parked outside in their parking lots, and onsite hydrogen fuel cells.