I have no idea about crossing the border with snakes so I will not comment on this however while CITIES have changed dramatically, and can be processed within 24/48 hours (even sooner in some cases) I am very doubtfull it will happen at the show unless you contact a breeder prior to the show and pick up your snakes at the show along with their paperwork.

Best is to contact a breeder that will attend the show and ask them about the procedure.

Not all breeders export therefore some of them will not be able to get the cities within 24 hours.