The solar flares won’t fry a grid that’s prepared for that. The mechanism is saturating the transformer cores with induced DC current, and that’s easy-ish to defend against (switch off the transformer when it starts overheating (and possibly cause a cascade blackout), or run it at below 90% load to have reserve. Short-haul lines aren’t susceptible, long-haul ones will hopefully be replaced with HVDC in time.
I see the chance rather in “energy auctions”; smart grid, knowing the supply forecast for next seconds to hours, adjusting energy prices per minute. So the freezer knows that there is abundance of cheap power just now, and it can afford to store the energy now, and sink the excess wind power flowing in. Or the batteries can play the role of a market speculator, charging when the power is abundant and discharging back to the grid for a markup when there is a shortage. Similarly, said freezer knows it can go from say -18 to -14 'C safely if the energy is overpriced at the moment, or decide that instead of risking a $500 groceries load it will play it safe and buy the more expensive power to be sure instead of waiting. The consumer then can select appropriate strategy for the household or device.