For those interested the NEC Nth America solution for this problem is called "Stranded Calls CCV" in the Call Center Worx. Once the last agent logs out, any calls left in queue are routed to the assigned CCV where they can be queued to another split, played an announcement, trnasferred to VM, etc...
As for how QMaster handles this type of situation I'm not too sure. Still haven't had the chance to learn that product.