Thinking a bit here.
Are there any traditions of playing games during family get togethers? Could you start a new tradition?
I wouldn't play any games that are intended to be played by four people or an even number of people.......like, say, Bridge. But Monopoly, Trivial Pursuit, or something else that can be played by an odd number of people...........
Or you could let the other four play while you run in and out checking on the kids........not as much fun..........depends on the ages of the kids. Or Bridge, but whoever was dummy last time gets replaced by the person who was sitting out.
Movies are also good - especially old favorites like It's A Wonderful Life, The Wizard of Oz, and similar CLASSICS. The kids see them for the first time and the rest of you can "remember" the first time you saw it (parents, possibly in theater) or on tv (possibly in black & white).
Offering popcorn, sodas, chocolate covered peanuts, hot chocolate, or something else as a snack while playing cards or watching movies would give you (or whoever) a quick reason to leave the room for a few minutes - if you (or DH) needs a minute or two alone. Putting the kids down for a nap or to bed early works, too.