Except this morning I re-counted, and realized that puts us at 17 around our tables, not 16. We can reliably fit 16. We can move the kids (2 are in booster seats with trays, so they don't have to be AT the table). It'll be tight, but we can make it happen.
But THEN! Just now I remembered that one of the single guys is coming. And I have consistently forgotten to count him. So now it's 18. I mean, we'll still find a way to make it fit, but holy heck this is cutting it close! Sigh.