What size pots do you have them in? Perhaps a transplant to bigger pots right before your vacation would hold them. When I transplant from 3 to 7 gal, they can go 7 or 8 days without water easily.
If you are going to transplant into a larger pot, you could try putting in wicks (cotton rope works well) that poke out the bottom, then stand the pot on a couple of bricks inside a larger container holding a few inches of water. My last grow was able to self water this way for 2 weeks at a time with no problems. Eventually the roots extend into the water & do their own wicking.