The Soviet Union was a totalitarian state before and during December 30, 1922, you can't escape that.
Besides that's an incredibly subjective assessment and it betrays your ideological sympathies on the matter. The Soviet Union just has to slowly ease off of some of the worst stuff and perhaps either continue or remake the liberal policies of the 20's USSR.
Beyond a certain point the USSR has to pull a China and ease off the command economy while keeping the political system around.
Okay, couple things here I need to establish.
1. I'm not arguing for or against command economics. Rather, what I stress is that we can't judge them from the examples of China or the Soviet Union, because both were totalitarian, where an economic system will be FAR less efficient from issues like corruption. When China economically liberalized, it had to release some grip. It has to tolerate some verbal dissent(complaining on the Internet won't get you insta arrested as an example) because of the costs to maintain those aspects.
2. And? What I'm saying is that the Soviet Union either has to BECOME Democratic, collapse from its inefficiency from totalitarianism, or somehow begin that way.
3. Other totalitarian regimes still had MASSIVE inefficiency despite using market economics(corporatist style, yes, but still market) because of their totalitarian elements.