Worth pointing out that this is 6800 Ultegra rather than the newer R8000 Ultegra Di2 groupset.
Two for one
Ordered. Thanks OP!
Cycle Revolution has it in Large for £8,999 and if their site reads right, you get 20% off if you add another road bike to the basket https://www.cycle-revolution.net/9231/products/cervelo-p5x-shimano-ultegra-di2-triathlon-bike-in-black.aspx