If your parents and your in-laws stay with you over the holidays how on earth do you deal??

(My long, ranty hormone-laced vent)
I'm starting to stress about the upcoming holidays. DH and I are trading off years, spending every other Christmas with his family across the country. Last year we flew to them so this year is "my" family's year. We are staying home and my parents are driving in to spend the holidays with us. DHs family is also coming to us for over a week. Our three bedroom house will have pregnant me, DH, LO, my parents and SIL. DHs parents will sleep in a trailer in the next town.

I'm starting to freak out. Our families are polite enough but their styles are so different. Different sleep schedules, activity ideas, meal times/styles, foods. Plus I'm starting to realize that having DHs family here and entertaining them for a week means I'm giving up my Christmas with my extended family. I feel like we should have just flown out to see them.

I'm dreading dragging my in laws around to my family parties (if I can get them invited) but I also feel rude taking LO and going to my typical holiday parties without them. I am considering telling my parents not to come but it's "their" year. They haven't had a Christmas with LO yet.

DH is stressed about it too so I know I'm not totally imagining it. He's very worried there will be a favorite Grandma.

It's our first Christmas in our house so we have no decor or existing traditions in our house. All my traditions involve going to other family members parties. I don't even know where to start with decor and I've never hosted a dinner for eight.

Besides finding spots for 8 stockings, how do you handle hosting in laws & parents?