Lots of interesting ideas here. To the actual question, I can only say that it depends on when and why. A PoD in 1917 is one thing, a PoD hundreds of years earlier that eventually happens to create a democratic Russia quite another. There is no rule saying that the Latvians and Estonians have to want independence: they will or they won't, depending on how they and Russia generally have developed, not to mention what's going on in the rest of the world (sometimes being part of Russia might be preferable to being part of somewhere else: IIRC, Georgian troops in Batum held out against the Turkish nationalist forces for some days so they could surrender to their Bolshevik allies instead).
All I can say with certainty is that it's mistaken to think that very large multi-ethnic countries never hang together of their own accord. India is a good example, but Iran is also a long way from being a national state. Our modern (western) ideas about democracy implying "self-determination" and national states were by no means ordained, and they might never have caught on at all.