This past summer, I moved long distance with my fish. In total the fish were in transit for 31 hours, and I didn't lose any of them. If you are planning a long distance move with your fish, you may want to give this a try.
I used various sizes of Styrofoam coolers, these are generally waterproof, and are insulating as well. My fish would be traveling in the back of a pick up truck, so I wanted to ensure they would be fairly warm. I also bought a roll of duct tape for the lids, airline tubing, air stones, and a battery operated air pump.
Each cooler was set up as follows: filled approx. 1/2 to 3/4's full of aquarium water depending on the fish. I wanted to save as much aquarium water as possible so I had saved 6 plastic milk jugs (washed very well) and filled them with water as well. Once the fish were inside the cooler, I cut lengths of airline tubing to approx. 18" each. On the end of each one, I put an air stone. These were placed in the cooler with about 2-3" sticking out and the lids were firmly duct taped on to reduce spilling, and so the lids wouldn't come off. Be careful not to block the tubing. This airline would allow me to quickly rotate the battery operated air pump between coolers. Every couple hours the pump was switched between coolers. This seemed to work very well in my case. The extra water came in handy to top off the coolers water level if one became low. I checked on the fish every 4-6 hours, they began to show visible signs of stress after 10-12 hours. I would recommend to anyone wanting to move long distance where your fish will be in transit longer than 12 hours to purchase adequate sized coolers, not what they will just fit into, but so they have some swimming room as well.
In planning the length of time your fish will be in transit, try to reduce this length if at all possible, move the aquariums last, set them up first. Save as much Aquarium water as possible, and add some stress coat to the water. If you have high strung fish, you might consider adding a small dose of tranquilizer to the water, to calm the fish a little, be very careful with it if you choose to use it.