Since when is there a chiyuv to go on a trip on chol hamoed. i was always under the impression that the purpose of chol hamoed was so that people who don’t normally have the oppurtunity to learn during the course of their regular workweek would have some extra time to pursue d’veykus with Hashem.
Trust me the kids never get cranky on a trip to the Bais Medrash (and the Bais medrash doesn’t get cranky either so it solves both of your problems chickpea)