HVR Z7U "Low-light" Settings

Being the novice I am, I need assistance in virtually all matters of videography. I will be shooting a Christmas concert (normal room lighting) combined with a candlelight service. The situation I have is proper settings for my HVR Z7U for the candlelight portion of the service. Making everything more interesting has me as part of the choir for the candlelight service, leaving my video camera running without an operator. The room lighting for the concert and service will remain consistent until the end, when the house lights go out and everyone will be holding a candle. After the house lights go out, the light will progress from the altar to pew after pew of everyone lighting candles.

Of course, I know using "auto" settings is NOT the way to go. The camera will be fighting to capture the "correct" light settings, with a mostly-dark image replete with video noise. I did encounter a similar situation when trying to time-lapse sun-to-moon (Ouch!!).

I will appreciate any and all assistance in determining what settings I should use, with the best probability of good imaging.

Thank you.