The question of the Sanhedrin and Mashiach is also dependent on the recognition of true prophecy, which can only take place when a majority of Jews in the world live in the land of Israel. I believe that if the majority of Jews did indeed live in the land, there would be enthusiasm for establishing a true Sanhedrin.
And there are opinions that, strictly speaking, the Temple isn't needed for these things to happen, but that the finding of the Ark of the Covenant, etc, will suffice.
At any rate, we live in most interesting times indeed. Other than that, you of course have much more knowledge than I about these things.