"I believe G-D will begin the process before the end of the tikkun. He won’t be able to hold Himself back, so to speak. This is the rachamim gedolim for akabtzech---tremendous mercy that speaks to that “one second I will abandon you and with incredible mercy I will gather you.” It is that “tremendous mercy” which tells us that, even before the tikkun is completed, G-D will have said: 'Enough is enough. I’m the boss and I declare that it’s over,' and it’s over.
"This is what we await, when G-D has had enough of the sinning, the relentless rebellion of mankind going against His Will and against the Jewish people. That’s when it’s gonna happen. He’s gonna be fed up with the whole process and end it. He wants to end it now."
Excerpt from Rabbi Kessin's shiur below, transcript can be found here.