I would probably dedicate the time to other aspects of the car cleanliness, I used to make the mistake of dedicating all the time to the paint in my concours days and losing points in other areas. 3 coats of EGP and a couple of coats or the Onyx will be ideal.
All depends on how dirty the car gets on the way down, you may get awy with a Quick Detail and wash the arches and wheels, other wise a whole wash and quick detail will need to be done. I would leave the dressing of any trim, tyres etc until you at the show ground.