Do that to a couple thousand wind turbines and yes, "better buy their gas now". Even better if you do it the other direction - take the brakes off in a storm, and you get https://www.youtube.com/watch?v=l3tqjuvy7i0.
There's a lot of interest in this sort of thing. https://www.wired.com/story/how-30-lines-of-code-blew-up-27-...
They're _currently_ buying Russian gas.
And they'd be able to prove that how?
The worst thing russia can do to get them to buy more gas, is to directly attack them. Do you really expect them to even talk to russia, if russia did that? Just the outrage (fueled by the media) would make people forgive the government the highly inflated prices of imported electricity, while they fixed the wind production. Russia literally has nothing to gain by doing this, and a lot to lose...