> The grid complains because it's suddenly lost hundreds of MW of load. For the DC to have isolation capability, it would need a load-sink which can consume roughly the same power as the DC in normal operation, and can take in that load at a moment's notice.

Thats why always have all the EVs be connected all the time (except the 20 mins they drive). EVs can provide demand as a service and take excess power whenever its available (instead of solar curtailment), and also provide an immediate source of load when events like this happen. Its a shame US is anti EV, it has the best systems at scale that can be leveraged to transform the entire energy ecosystem.