Has the OP reserved a specific seat? If it's still possible to do so, this could marginally help, so it *might* be worth paying for an advanced seat assignment or better seat if possible.

If the OA CoC is available online (and in a language one can read), it might be useful to look at what they say about how oversold flights are handles and what priority orderings OA uses for IDBs. Obviously EC261 regulations prevail, but it would be good to be familiar with this particular airline's procedures in such situations. If the delay is long, an IDBed passenger could be entitled to meals or even a hotel room.