90K is the recommended service, Recommmendations have tons of margin so they don't get sued.
There is a thread in the 100's section on pictures of T Belts removed at various mileage.
That said, If I was interested in it, I would drive it back and keep driving it till Robbie had time to do the replacement.
Ken Romer - K0ROM
02 Kimberley Kamper
09 BMW Z4 sDrive30i