(((NG))) I know it's hard, but I still remember someone here telling me when my h moved out that it was not the end and that maybe moving out was part of the journey my h had to take to get through his crisis.
Try to plan something fun for the first days the kids are gone. A day at the spa, maybe?
Your h will also be without you and the kids for most of the week. That will give him lots of time to think about what he's doing.