You can actually do this from the release of the game.
You can breach into the museum in any time you want (before the Night 2), you just need to perfectly aim in the space gab between the door and it's frame, and you can then remove the plank with crowbar.
You can actually finish a whole Night 2 by doing this, but if you take the Family Photo, it just disappears and you wont be able to continue the game, when you'll ACTUALLY be in Night 2!
I know that every door has this gab (wow), but wont it be possible to put some thin invisible wall in there, before the Night 2?
Thank you 