It would be really dumb to do this now!..They got to harden everything to withstand anything just short of a gamma ray...( wouldn't matter much then cause we'd all be toast).
We are in for some probable, precarious natural disasters and perhaps, threats from some humanoids.
Other than the actions of humanoids, it's not a slam dunk that any carrington like event would only effect the side of earth where both magnetic poles are...which is the other side from the perspective of the America's. If the worlds grids go, it will effect us too in one way or another.

The "world alliance" are not my allies.
"UN-based Alliance" is weasel speak for looters (which is objectivist for robbers and thieves;^).

I suspect people will find other media of exchange. I agree that physical cash is inefficient, but it should be people's own choice. I think it will be. They'll use quarter ounce gold coins the same way they have since ancient times.