the bamboo will be fine. if you can dig early/late in the day it would be best. anytime you do this the plants will have some amount of shock. try to keep out of direct sun. if it is really that hot, you'll probably be worse than the plants.

When you dig, have a lot of large plastic leaf bags with you. Soak the root ball with water as soon as it's out of the ground, put the root ball inside a plastic bag, and lay the plant in the shade while you're digging others out. When you transport them, use twine to spiral wrap the culms and leaves tightly so that they don't whip around in the wind (this minimizes moisture loss and wind burn of the leaves).