This question is a very good argument in favor of arranging setups that don't need daily attention, even if it means more expense or work in the short-term. I don't mean this to sound preachy, just as a word of warning to anyone else who is reading this. It's difficult to take a vacation if your setup is complicated to maintain. Everyone needs to take a trip (or is unexpectedly called away) once in a while.
How long will you be gone? How much space do you have in the fridge? If you fridged them in fairly large containers, they may be fine without any water changes.
Another option might be to take them to a friend's house, each one in a large bucket. The friend could do daily water changes and occasional feeding. If they have AC or a basement, temperature should be OK.