I do it all the time for catering. I just put a bungie cord around the pellet hopper to keep the lid closed and don't bother with removing the pellets. Its a good idead to remove the shelves and clean the firepot as stated before, and you will only forget to remove the grease pan once...
Cookshack FEC-100, Weber Genesis, 4'x6' Santa Maria grill on a trailer
Placed with new owners:
18.5" WSM, XL BGE, UDS, 22.5" Weber OTS (x2) 22.5" Weber Performer, Traeger BBQ075 (x2), Yoder YS640, Bayou Classic Cypress Grill