Also all it takes is one station to fail, that could cause a huge blackout like the one in 2003. Our entire electricity and technology grid is only as strong as its weakest point.
I’d think 20-30 hours warning would be sufficient to implement emergency “hardening” even if it meant shutting down the grid and temporarily cutting connections during the height of the storm.
Emergency generators could be secured for hospitals and other emergency services in that amount of time, and shelters could be set up for the populace. Happens all the time with ice storms and hurricanes.
I’d be willing to endure a day or two without power to avoid such a dire outcome as having large portions of the electrical grid destroyed. I do it once or twice a year due to normal weather events here in the southeast anyway. What’s once more?