Generally, when checking the camera, you are aiming to be on and off as quickly as possible. When done you can optimise by waiting 2 seconds before flicking to check again. This way its frequent while not taking too much power.
The camera blackouts are caused by movement within the camera so it's either Foxy progressing out of the cove or Bonnie moving in and out of the camera.
It's entirely random to when Foxy wants to. There's been times where I've still gotten her 3 times in one night, coming up to a 4th one by 5AM. Generally, you want a run where she appears around 2AM and one where she appears around 4AM, but it's entirely luck. The camera is still necessary but the AI can still decide to screw you over either way.
