So far, there seems to be no animatronics in the game that can forcefully pull down the monitor. When you check the monitor, you are invincible. and the power can definitely last until 6:00 without being depleted
No, Mangle can't do it. She'll wait for you to put down the camera like Chika. As for Foxy... when you open the camera, he can't move (even if you're not watching pirate cove)