It’s important early on in the rehearsal process to decide on the actual space you are going to use. Even if you can't rehearse in the actual space for the whole time, be aware of what set etc is going to be onstage. Draw some diagrams to help you plot your set.
Suggest a new direction to the group, and make sure you explain how you can't be seen or heard - this could be bad for the whole group.
If you can't see the audience, they can't see you!