Let's consider your scenario - and we'll make it one night a year to up the challenge. Well let's see. There is exactly zero domestic demand - since that is all taken care of by home solar and batteries. There is no commercial demand - that is taken care of by solar and batteries as well (indeed, they are already doing it themselves now).
So what's left ? Industrial - and even then only the few 24/7 factories. You ONLY need enough gas generation for them. But let's assume one or two can't be met - there's just not quite enough gas power.
Results: an economic loss equal to roughly a trillionth of a percent of what we're spending on coal every year now.

I think we can survive it.