ZED can be quite misleading sometimes (pessimistic).
See if you can book online commercially, the price of tickets might give you a clue. Worst case, phone your airline's commercial ticket line, and say you're staff travelling standby, and ask if it's wide open or not.
Always best to leave yourself a flight in hand incase you don't get on. Usually the guys on the gate will give you some priority for the next flight if you've already missed one.
Commuting can be stressful. Good luck