You AND the kids might enjoy the holiday more without him.

You can practice saying things like "I would like you to come but I understand if you don't feel comfortable going, we will be fine on our own".

"I wish you weren't moving out but I know it's your choice, I hope you find what you are looking for."

"I would prefer to save the marriage but I know that's not how you feel, so I wish you the best in life."

Just state your preference, but then let him know you've dropped the rope and are not trying to pull him back.

AS long as you pull on the rope they pull away; sometimes when you drop the rope they fall over or start walking back.