pads and that counts for something.
A 3.5 hour drive might have the brakes only lightly bedded in. I can drive 3.5 hours -- on a highway -- and hardly even touch the brakes and certainly not in a way that brake bedding in calls for.
The bedding in process wants to get the pads nice and hot which will drive out the more volatile compounds. These turn to vapor under heat and tend to act to prevent the pad and rotor from making good contact.
Furthermore, if one is not careful uneven material deposition can take place and then the brakes will pulse when used. This can happen for instance if on your 3.5 hour drive you have to make an emergency stop. If the brakes start pulsing when the pedal is applied the only way to deal with this is to resurface the rotors.
I would attempt if not a full Pagrid bedding in procedure as much of one as I could before heading out.
Once at the track then if you can arrange it complete the bedding in process before you get serious with the car.