I had the same -- arguably silly -- idea myself, of a libertarian Soviet Union.
But, I think an anarchistic, Bakuninist Soviet Union would be a bit more plausible. But maybe more minarchist, rather than anarchist?
With the level of economic development Russia had, socialism would be full on anarchist or OTL-alike.
Edit: And it might be Kropotkinist instead, who was alive at the time.