It's amazing how many well intentioned people cannot grasp this very simple point. There is no way to run a grid solely on solar and wind. Therefore the choice isn't between those and nuclear, it's between nuclear and coal/gas.
A fully renewable grid really is terra incognita, no one's done that before, of course there are a lot of open questions. But being a trailblazer might pay off handsomely if it does work out well, as others will want such a grid too.
Those power plants and the Berlin airport went the way they did because of the immense corruption around such extremely large, expensive, long-term construction projects. There's a whole sector in construction exploiting the inane legislation around these things. There's no way that's going to change anytime soon, and it's not a purely German issue either (as the European nuclear projects demonstrate).
At least so far, the push into renewables looks like it will require very few such monolithic large-scale projects at all, and even then, they should be a lot less complex and cheaper than the current generation of nuclear plants (and a lot faster to build). A lot of the concepts for storage are also well-suited to a distributed build-out, and that involves making people order a bunch of things from China, set them up and network them, which we're all doing all the time anyway and which tends to works pretty efficiently. The whole thing is by no means a guaranteed short-term success, but I'd say the chances of this working out nicely aren't bad at all.
Either we got a lot worse at building complicated stuff, or the real reason for building delays is NIMBYs protesting and lawmongering.
I also expect this quantity to be much lower than it would've been last year, as I also expect significant effort to be put into both improvements (e.g. home insulation) and alternatives (e.g. renewables).
If we can insulate 1% of the worst houses and apartments, that's still an improvement, in that less money goes to Russia.
If we can get 1% of our needs from LNG terminals built in the next 6 months, that's still 1% less fuel trade with Russia.
If fuel oils, benzine, diesel, biofuels, and new wind turbines combined can substitute 1% of Russian natural gas, that's 1% less money going to Russia.
The USA put speed limits on their highways in response to a fuel crisis, if we do that with the Autobahns and it only reduces Russian imports by 1%, that's 1% less of our money that ends up funding the Russian government.
While coal is much worse for the climate than natural gas, a short-term political need to deal with a warmongering fuel supplier can override that, so burn it and starve the Russian government.
Etc.
It adds up. Even if Germany sill buys 90% as much Russian natural gas in December 2022 as in December 2021, that's still better than buying 100%.
I'm relaxed about nuclear power, but unfortunately this is not the majority position and hoping for them here is wishful thinking. Also, nuclear just can't be constructed fast enough to be relevant for this winter, not even with a major increase in their political acceptability.