Hi Angela,
We leaft our three at home for 10 day this spring while we flew to Japan to visit Missy and Paul (daughter and son-in-love) I was a nervous wreck!!!. My son checked on them and played with them each day and kept them fed and watered, then he and my daughter-in-love spent the night once or twice. Everything went FINE. I missed them but I am sure they are much better off at home. Mostly they just sleep anyway!!
They will be fine! I bet you will worry before you leave and part of the first day - then you will relax and maybe miss them but know they are fine. Have a GREAT time Family is the best at cat sitting!!