Not sure if this helps anyone but I called Tesla Solihull earlier to try to get my delivery location changed from London Heathrow to either Solihull or Birmingham.
They couldn't change it. All Model 3 deliveries will be from London Heathrow for the considerable future. They told me the team down there have been trained on the delivery experience and they want everything to go smoothly.
He said I could cancel and put my order back in in a few months time but I said no way, I'll take the pain and go down via coach or train or something.
He also said he had no info to share regarding when I would get "the text" or "the call" and have my reservation turn into an actual invoice and VIN. He told me everyone is in the same boat, he and other guys at the Solihull showroom are waiting on info for their own cars.