I have to say that if the extra is a child normally the restaurant is very good at trying to place that child,
We went over and at the same time had friends staying for a wk while we was there, the friend ended up being very sick and having the doctor out twice and so we liked after the child,
Of course we had a lot of Adrs booked so we decided we would take him and hope for the best at every place they accommodated us, they explained we might have to wait a little longer for a table but at the most it was only 10 mins and that was at chef mickeys for dinner.
So not all hope is lost if your willing to chance it.