Husband wants to leave me to take the kids to my parents by myself

I have 3 kids, 7 and 4 and my 5 months old baby. My step son is 18. He broke his leg and sprained his wrist playing hockey and is upset he has to be benched when this is his senior year. He doesn't want to fly to family because of his leg and my husband doesn't want him spending Christmas but himself with a broken leg so he's wanting to stay behind. I can't rangle three kids in an airport by myself. Especially a baby. My husband and I are in a lot of disagreement here. My stepson is deciding not to go. If he needs any help my husband's mother lives right up the street. We already told everyone we were coming. My mom is expecting us and I can't take all three by myself.