What have I done.

dragon300zx

So I just checked out the site of a wedding I am shooting in a few weeks. The reception is in a hall that is right next to a river. With 180 degrees (2 of the 4 walls) of complete glass walls, during the day, letting in lots of harsh light. Which means Imma need me some light. I'm waiting to hear back from the owner with a size of the room but I'm wondering how much light I will need. Anyone have exp shooting in these kinda conditions?