Though when selecting individual locations for wind, different locations favor different time of the day. And of course solar output varies significantly east/west and based on local weather conditions. That all gets modeled ahead of time and in practice get reflected in market rates.
Even then, I do really expect a category of "peak demanders" to appear soon (storage is one kind, but there are other things one can do with intermittent almost free electricity). That will help increasing the spare capacity.
I suspect an outgrowth of oversupply is storage will ramp up based on consistent access to very cheap rates. It makes a huge difference if you’re paying 0.4c/kWh or 4c/kWh to charge, especially when storage is significantly less than 100% efficient.
That said, consistent very low prices will likely result in someone using most of that power for something even if the power plant operators aren’t making money during that period.
You can model this as (cost per kWh of cheapest alternative) / (cost of rentable per kWh) = marginal oversupply you want. So, if hypothetically Solar was 2c/kWh and peaking natural gas was 6c/kWh then you would want to add more solar until 3kWh of new Solar only offset 1kWh of natural gas with the other 2kWh being wasted.
Which does not mean 2/3 of total solar energy would be wasted. Further, storage and energy markets also complicate things. However, it does illustrate why you want an over supply of the cheapest option even if not all of it gets used.