If anyone else is interested, Tough Crowd is now available for download from Audible.
I've started a new thread, as some people may not be aware it's available. I had been checking and couldn't find it under pre-orders but searched again and found it today.
As a warning, the Audible search engine doesn't list the book at all when you enter the book title or Graham's name. It just flags up the book shown in my screenshots but the search results will list Tough Crowd as the second result. 😐