Turning on and off quickly is difficult and/or expensive for all of CCGT/OCGT gas, coal and nuclear. Turning up/down is much less so however, and in reality that's often how it works.

That is not true. Wind output is highly correlated across the continent. Days in which wind output is very low happen regularly. In fact, every couple of years there is an entire week like that.

Relying on this seems to imply strongly overbuilding for the worst case. Meaning all regions should have enough wind power capacity to compensate for the occasional lack of wind everywhere else.

The advantage of nuclear is that it will work almost certainly, albeit possibly at a high cost. We should continue to invest into wind and solar where that makes economic sense. On the off chance that a magic energy storage technology comes along we can then phase out nuclear again. However, betting the future of an entire continent on the coming into existence of such a technology is wildly irresponsible.

Well Europe is already invested in LNG. I imagine there will be more LNG terminals being built despite it not being great for the environment.

Ex: https://www.seattletimes.com/business/germany-announces-new-...

> Germany built out their electrical grid with twice the Solar capacity it needs to power the country.

Not so.

Germany used 568.8 TW⋅h of electricity in 2021[0], or 64.9 GW on average.

Even the nameplate capacity of PV is 58.7 GW, so less than use rather than double it, but the actual capacity factor — which is included in any reasonable definition of the capacity needed to power a country — brings it down to just under 10% of demand.

All renewables together are just under half of demand right now.