After (remote) recording a female choir in a neighbourhood church yesterday, I realized how spoiled I am in the normal, "controlled" studio environment. There, I know the environs, and "unknowns" rarely occur and/or get in the way of recording critical musical events. Often in remote recording situations, there are imminent problems with the environment: hum (due to lighting: MH/flourescent, HVAC, etc.), leakage (traffic - air or ground, passer-bys), exteranneous settling sounds (wood creaks, environment reacting to temperature changes, etc...) I often wonder how it's possible to do critical recording in these environments? Do most people book time in these places long after the city goes to sleep? Shut down the HVAC (if possible - most new buildings, this is impossible

), players perform by stand lights/candlelight? How do you deal with these impediments? Seems there's always a catch when moving gear out of the familiar, and into the "real world".
BTW, this is geared towards "critical" recording - not R&R (amps/kit) - large dynamic range, and low noise required...