That’s why a broad basket is preferable to a monoculture of production.
Where I live is a perfect microcosm of this - in the summer, we get ample power from our solar array, but in the winter, when it can be dark and raining for weeks on end, it doesn’t come close - so I’m building out hydro and wind, as when it rains, a stream appears that we can harness, and the wind blows.
The same applies to renewables at grid scale - overdependence on a single source is absolutely risky, which is why most renewable energy efforts involve quite a bit of diversification.
So use that while we can and leave the fossil fuels for when renewable are cut off from the sun.
I wonder how much wind there would be under these circumstances though.
“It can't work if you do it that way" is a pretty bad argument if nobody actually does it that way. Maybe you are accidentally misrepresenting reality in order to support your world view here, but if not please go somewhere else, where facts don't matter.
As others mentioned: every nation that does renewables is looking into robust energy mixes and this (at least in industrial nations) includes catastrophic scenarios as well).