If you are flying, I might think about sending them bare root via FedEx or something. I know FedEx has long triangular boxes that pitcher plants would fit in.
I wouldn't leave them movers... I think that would mean dead plants or lost plants.
If you are driving, I would leave them potted if you can. If you have no room, maybe pack them as if you were going to ship them. Wash the soil away, wrap the roots with a little moist long fibered sphag ( or wet paper towels ), put in a ziplock bag. You might have to use a kitchen trash bag or bread bag for the pitchers and then put in a poster tube.