The infra red isn't an emission in terms of cameras, it is a receptor designed to read the lower spectrum, with lights out it boosts that, there is no risk to light cycle with a camera (unless it provides it's own lighting as many do, but then you can mask or cut off the LEDs).
I am about to start flowering in the coming days, at which point I'm going to greenlight the room so the camera can carry on recording while they sleep, doing exactly what you are looking at doing. I have been told that if you remove the red lens layer in a digital camera then it will do proper nightvision without the need for green light, so I'll be testing that first to see if there's a way to grab footage without any lights (I know the green thing is supposed to work, however I just don't trust the odds of slight spectrum overspill)
