Lucky, it's a good question, and here's a good answer.
The "main" couple -- the out-of-towners -- moved away last year. Our children went to school with them from pre to K. We took a 2-family vacation last summer with them. We email and chat with them regularly. So for us NOT to show on the one weekend they're out visiting, well.....
Where we're going has a dining area -- this was a regular event with the couples in question -- with a big, sort of oblong set of tables. So it will be 14 adults around an area, with 7 or so kids clustered at a kids' table with coloring and nintendos and so forth. So we may well sit next to each other, but can chat with people across or next to -- or, as DB Coach strongly encouraged, each other from time-to-time.
This is in lieu of a "date" WAW wanted to go on -- was quite insistent about, even when she was enraged by the nasty email SP's Mom sent, where we WOULD have been staring across the table at each other.
This way we figure we'll have a kind of cushion in other people.