Wind blows around the clock and solar runs most of the time we are awake. If renewables are super cheap but storage is not viable, can't we simply overbuild?

Solar drops hours before daily air conditioning demand, but wind might do it. I always thought wind depended heavily on the solar cycle, but apparently Europe found it dips 20% or less at night.

Solar is still delivering 50% of peak as late as 5pm, and peak air conditioning is between 3-7pm. It's not a perfect fit, but mix in some time of use rates and (as previously mentioned) wind and it seems like you could do it. In buildings with decent insulation, cooling load is not hard to time shift.

Also batteries are critical for Solar to be viable generally anyway, but not ideal for sustainability.

Wind is not as predictable as it seems, and most importantly, you don't get to control the production except for clamping down when you overproduce (this results in negative prices on the market and such).

Then you have to add transfer issues, and you have situations where North Germany is exporting, while south Germany is importing, and there's a lot of fossil fuels burned just so you have capacity to keep the grid in shape.

There are of course alternatives, like controlling demand via methods such as informing people they have to reduce power usage ASAP or get cut off (hope you didn't just start washing machine or put food into electric cooker)

In my ideal future, demand doesn't need to be controlled that forcefully. Tank water heaters, electric cars, air conditioning, furnace fans, and dryers can all be networked and choose to operate when power is cheap. They can soak up spikes in production and back off in troughs. These things are also the vast majority of residential power (the only other heavy hitter is cooking)

Improved distance transmission would definitely be a big help.

No. It cost money and land (environment) to build them.