Kerensky was committed to crushing the soviets. His government would have likely been a Weimar-style parliamentary republic, struggling to remain coherent, or alternatively succumbed to the right-wing forces used to prop it up.
The key to soviet democracy, I feel, lies in the Soviet Alliance that organised October and the Brest-Litovsk treaty that tore the alliance apart. If the Left-SRs and the Bolsheviks had remained working together, they likely would have not only won the Civil War sooner but also been forced to play off each other in the soviets in a sort of two-party democracy.