I just want to clear up two misconceptions in this thread.
1. OnQ has no way to catch a consecutive reservation. You need to tell the property somehow be it a note on one of the reservations that there is another segment, by calling in advance or at check in. Either way OnQ is not that smart and there is no way it can flag it or do it by itself. It's a 100% manual process.
2. OnQ cannot "link" reservations. It's also a manual process where someone on property needs to make sure that reservation #1 is checked out/modified/extended and that reservation #2 is checked in/dealt with, etc.