Well I am not so sure it will be as small as you suggest. At least initially. Bitmain and ViaBTC ain't nothing to fuk with.
A split is a split. Bitcoin Cash is happening regardless if it is 300$ or 500$.
A fraction that becomes meaningful in the future is also a possibility.
Otherwise I agree that what you describe about the 2x part will happen.
RE: The Hardfork will happen: Bitcoin Cash, SegWit2x, ViaBTC and why I want a Bitcoin chain split.