I think it's fair now you have dc especially (and if you have more dc and as they get older) now you have dc to split it 3 ways so you're only at theirs 1 year in 3
1 year at your parents
1 year at home - you could invite in laws to yours?
1 at theirs - and make adjustments that maybe will make things a little more comfortable for you? Eg a "present" of Xmas themed lap trays for everyone to eat off
My mums lot are very "take us as you find us" and their homes are very welcoming...but kinda chaotic
Dads lot (this is prob where I get the ocd from - not even kidding!) everything is VERY clean & tidy and precise and timings are organised for such occasions.
My parents argued about MANY things, the way the different families did Xmas and other such occasions - I can't recall one such argument! They just acknowledged/accepted different families did things different ways.
However with dad being army and depending on what he was working over Xmas meant many Xmases were "just" the 5 of us (parents siblings and I) - I say "just" as to my parents this meant a "quiet" Xmas seeing as they're both from big families (dad one of 5 mum one of 6) plus mums side at Xmas was also, when I was younger my great gran who was still alive then and lived with my grandparents, and also 2 "maiden aunts" who were, well one was great grans sister the other from my grandads side.
Considering they lived in a 2.5 bed tenement in glasgow it could get quite tight! 
I remember one Christmas where EVERYONE on that side was still alive and present for Xmas and this included my dad and my mums siblings spouses/partners plus me and siblings and all the cousins (11 of us alone! This particular Xmas that inc 2 newborns) it was chaos! But brilliant fun and I remember it very fondly especially as great gran died the following summer. She was bedridden at this point but her room was never empty that Xmas day and she loved it! There's a wee photo of her BEAMING holding the newborns in her bed with wee Santa hats on and she's got a Xmas cracker hat on and she's a baby in each arm.
2 dining tables were squeezed in and a kids table was set up in the bedroom my mum used to share with her sisters. "Chairs" were some actual chairs, footstools (called pouffés then), a laundry hamper etc
We had to walk over the bed to get to our table and then adults were handing us stuff over the bed to eat got quite tricky when it came to the gravy but we managed I think mainly as we knew if we spilled it on the eiderdown gran woulda KILLED us! 
With the ocd, yes I would struggle with the scenario you have illustrated, but I would suck it up for the day and then disinfect everything when I got home without them knowing
These are your child's relatives, they don't sound abusive or unkind in any way. Compromise is key here - if you're compromising dh and his family have to also.