How many people got cut from the reservations?
If it is only one or two, it may be worthwhile to show up with your friends for their ADR anyhow and see if they can increase your table size at the desk.
A couple of years back I made a number of reservations for 3, but at the last minute my FIL decided to join us as a surprise. We went to each meal and explained that we had a last minute surprise guest and we were now 4 instead of 3. No one had an issue with it. Then again, there really aren't tables specifically for 3 anyhow, so its not like it takes an extra table away from someone else to use the 4th seat that is already there
Of course, if you are talking about a fair number of people, this won't likely work for you...