What to do about the holidays with split family?

Ok long story short. My parents have been divorced for about 6 years now. Normally they deal with it every year. We all travel up north (most of us live near or around phoenix) to prescott to my sisters house. My parents have been dating on and off since the divorce, in January they got into a fight and now won't speak to each other at all. I just roll my eyes most of the time. Well the holiday's coming up and my dad has said he might not go up north. I'm much much closer to my dad than my mom. I told my dad it's important that we all spend that day together but he keeps saying he's going to just eat at Denny's. WOW! What do I do? My husband says we will just spend it with my dad where ever or what ever that means. I hate missing out on seeing my family. Even though they live close (my mom and dad) I only see them a few times a year. Plus my other sister comes (she lives in SC). My sisters house that we go to is so awesome we play football and Xbox and just spend the whole day as a family. This would be the first year in over 10 years it won't be the same. What to do?