The more precautions you make the better.
You probably have little to worry about. I transfered 2 clowns, 7 chromis and a dottyback in a 15 gallon tote. The trip was well over 6 hours without any heaters, air pumps, or water movement.
I might even consider just taking a few buckets of tank water stirring them violently with something to infuse air and just dump it right back in the tank. Do that once every hour and call it a day.
Also, keep in mind many of our tanks inhabitants are shipped in plastic bags of 1 gallon or less of water and it can take up to 24 hours before they are unpacked and acclimated to a tank.