The only thing that will put this pipeline back into operation is rehabilitation of Russia, which will involve unconditional withdrawal from Ukraine, apology, $350bn of reparations, and a war crimes tribunal.
Or a new German government, but your option seems more likely.
That's within the realm of possibility I guess. The three parties in the current government are struggling quite hard to find a common strategy to manage this crisis, so it's not entirely certain that they'll make it to the next regular elections, and the far left and right have largely positioned themselves in favor of taking both Nord Streams online and appeasing Russia, and that view is apparently also held by part of the conservative electorate, who might drift rightward if the crisis deepens. If there were elections in late winter, who knows how that would turn out, especially for the AFD party on the right.