I don't think we need to expect to come to any sort of agreement about the prologue. We will probably need to agree somewhat on the following scenes, because depending on how one scene ends is will dictate how another scene begins...sometimes.
And as for the meeting of Gandalf and Bilbo,
I think we need to have the whole "What do you mean, good morning?" discussion. The hobbit would scarcely be complete, much less begun, without that.
So, I believe what you should say now is, "What comes after the prologue and before the first dwarf arrives?" And if that is quickly decided, we can go on...