Since I know you have no where else to move them and have to do it now, I would move them all at one time during the night and put a baffle in front of all of the hives. Here in Florida I cut a piece of palmetto, including the long stem, and stick it in the ground. Being only 20 feet they will smell the hive they came from. There will be some confusion at first but if there are no hives in the old location they will figure it out.
Jim Altmiller