Thanks for the responses, it is what I had figured. Later is not great as I have a connection HKG to LHR which I would rather not miss. I would probably accept a Y downgrade as I am returning home after 2 weeks on business. I am hoping my status and price paid for the ticket will help my cause but I will do as you suggest and book in as early as possible (48 hrs I believe with CX) and I can also get to the airport early as well.