Is it even possible at current time?
or am i just bad at managing bun and chicken

I wish it had a quick retry button when so i dont have to go through the game over screen, main menu, and custom night

Kinda. I have done it, but it's mostly luck-dependent. You basically have to hope that Bun and Chica don't take their sweet time with their attacks so you can deal with Foxy. I would go into a bit more detail, but I'm feeling way too lazy for that xd. There is a pattern you can follow which depends on who attacks second in the early hours of the night. You would preferably like it to be Bun, Chica, Foxy, and lastly Freddy, so you have enough time to deal with Puppet and repeat. If it so happens that Freddy attacks rather than Chica, restart, because it's impossible to respond to Foxy before she just obliterates you before the night even begins. I have also noted that Bun seems to almost always attack before Chica, though it does depend at times; if Chica arrives earlier in the vent, she can manage to attack before Bun. -w-

I think not. I mean it's possible, but you need to get very lucky.
Because around 1AM they don't let you take off your mask, Chica and Bunny attacks in tandem, then Freddy showes up. And when you want to crank Puppet's music box, shit need rebooting. Then you die from Foxy 

It's possible with enough practice. I only wind the music box right after dealing with foxy, or i know that freddy will attack next.

I've beaten it, I posted the video in another thread. Here's some tips.

You can't crank the music box unless both Penny and Carmen are not in your vents.

Bjorna let's you crank the music box when her jumpscare is primed. The strat I did was 2 stages of crank and then go for a flash repair. The repair will happen in the background while she's trying to get you.

The bongs you hear indicate either Bjorna, Carmen, or Annie at the front entrance. You want to check these almost always and as soon as possible(though I didn't always because I believed it was Carmen, since she just reset) Multiple gongs can happen at once.

If Annie is in the hall, always attempt to do her minigame, even if both the animatronics are in the vents (if you let Carmen or jumpscare Penny you while Annie is there, you lose ) 99% of the time you will not get attacked by the other animatronics once you start flashing Annie.

Once you do the Annie minigame, you have a small window to crank the music box (one to 2 stage cranks) b4 the other Animatronics try to jumpscare you.

 2 stages of Mary is also about the time of the vent sound, which you can time to basically get an instant jumpscare attempt instead of having to wait and getting good repairs in.

I hope these help whoever is trying it. Not a whole lot of rng for this strat, but you might lose a few times