Noted 
And, in fact, the Soviets set up first a Provisional Finnish People’s Goverment (the “Terijoki Government”) and then the Karelo-Finnish Soviet Socialist Republic (Otto Willie Kuusinen was named president of the republic) in 1940.
True. However, that government quickly faded into obscurity as even the Finnish communists didn’t like it.
In fact, the war made the former enemies reds(communists & socialists) and whites(conservatives and liberals(*) to forget their differences and join against a common enemy.
This might move this post slightly to GD territory, but the current situation in Iraq seems to have some similarities with the Winter war.
Before the Winter war neither the reds or whites much liked each other as both sides committed equal atrocities against each other during the 1918 civil war. But the Soviet attack changed this.
The Iraqi people now have an outside aggressor that sets up a provisional government that nobody likes. Plus they seem to have stiff resistance going on.
In fact this might be better for them in the long run, as they forget their internal differences and focus on getting rid of the occupiers.
The above might sound somewhat callous, but U.S. already has democracy but Iraq doesn’t and the above might be the only way to unite the people there.
*)liberal = libertarian in europe