My parents are divorced. My FI’s mom lives far away and there is no expectation of us going there, but he celebrated everything with his grandma for a while before he and I were spending holidays together, so we factor her in too.
His grandma lives about 15 minutes from us, my mom is an hour away, and my dad is another half hour away further than my mom (though with holiday traffic, those usually about double).
Thanksgiving with my mom
Christmas Eve dinner with his grandma (he’s always had Christmas Eve dinner with her- his whole life). Drive to my mom’s after dinner.
Wake up Christmas morning with my mom and do presents/breakfast. Waking up Christmas morning is SUPER important to her.
Christmas dinner with his grandma
Day after Christmas with my dad (when my parents split and worked out custody and all that fun stuff, my Christmas celebration with my dad was the 26th, so we’ve just kept it)
Our birthdays: We do that just us!
Their birthdays: Whoever’s birthday it is (my mom’s is Thanksgiving this year, so thank goodness that’s already her day).
We have already started to tell our families that once we have kids, they will have to come to us – we won’t do this driving around!
Have you asked your DH to help solve this problem? If his parents have been divorced for a while, he probably has experience with it and will have ideas. My parents split up when I was 8, so although scheduling time is hard, it’s sort of second nature. He’ll also have a better idea of whose ok with what (notice my dad has less time than anyone else – it’s because the holidays aren’t as big to him, so we make up for it other times during the year!)
And I echo @Westwood: get hungry! Because splitting it three ways is a TON of food!