I am optimistic about the potential to shove consumption around within the day-night cycle - particularly if the shift is consistent.

So am I. Chargeable hybrid cars can do most of that.

About the longer term (synoptic) variations, what's left of those after the European supergrid, can be taken care of by gas turbines, but burning electrolytically produced hydrogen from excess wind. Yes, an inefficient solution, but if we're talking about 10% of production we can live with that.

I see you didn't mention the annual cycle: it's a biggie, and nuclear isn't very good at following it. Wind -- or rather, a suitable mix of wind and solar -- is much better. And I'll say again what I said before: most of our energy use that produces CO2, like 3/4, does not involve electricity. Like space heating, where there is a huge savings potential through better building, heat pumps etc. Also, process industry and metallurgy. Bringing down these uses will involve electrification, which will raise electricity consumption, something I do not see in most plans. Something to be aware of.