The range that your camera will see in the dark will depend on the sensitivity and spectral response of the camera and lens combination.
Some cameras have a better IR performance than others.
For maximum performance choose IR sensitive cameras. The human eye cannot see infra-red light, however most mono CCTV cameras can. As such the invisible light can be used to illuminate a scene, this allows night time surveillance without the need for additional artificial lighting. Infra-red also provides many other benefits above conventional lighting. The infra-red beam shape can be designed to optimise CCTV camera performance, as such it is important to remember to design illumination for the CCTV camera and scheme.