I know this is an old thread but I have dealt with situations like these.
You may be better putting the NTG 2 on a stand at the speaker and either :
1) use something like a Sony UTX P1 transmitter. If you’re doing that you may be able to use the same transmitter box to get a direct XLR mono output from the in house desk then you can stand wherever you like with your camera.
2) Still with the NTG on a stand at the speaker, run an XLR cable along the wall to your camera.
3) Use something like a Fostex MR8 and take a recording again from the inhouse desk then resync later.
I have an NTG 2 and wouldn’t use it in the way you are doing here.