Again, my understanding is that heating is what drives most of the natural gas consumption in Germany.
https://energypost.eu/no-energiewende-without-warmewende-making-germanys-heating-emissions-climate-neutral-nearly/
https://www.wingas.com/en/raw-material-natural-gas/heat-from-natural-gas.html
So, no, it's not as simple as just building more nuclear power plants.... you have to retrofit the way most German's heat their homes. That's not an overnight fix.
Of course, now that Russia is doing what it is currently doing and the Germans are putting NS2 on ice, that may be a catalyst for Germany to diversify itself energy wise, which in the long run will actually hurt the Russians.
Would you rather they just buy the Russian gas then?