I think it's possible. It has happened to dp and myself. I was adamant I was leaving before Christmas. Had a thread, sought a solicitor. Got papers together, rang to claim benefits, hid documents- the job lot.
Our relationship has been hanging by a thread for years. I think only the stress held us together......
And by that, I mean life was too hard to realise how shit it was.
We have had some monumental talks though. Hard, brutul, truth, no matter what.
We are both really committed to changing too. He has pa tendencies and I have spent a long time being emotionally unavailable.
It is hard, but this is the closest we have ever been. It's quite a different relationship.
It has took a lot of facing up to stuff that has been deeply uncomfortable for both of us, and we keep slipping up by going to our default settings at times, but we are learning to recognise it in ourselves and much more open to the other pointing it out. 
I don't think it's something that can be done easily, if there is a lot of issues, or one person isn't interested.
I liken it to a death by a thousand cuts. We were hemorrhaging and plasters were just not going to help. Up until quite recently, we began to think that no matter how much we talked and tried we were hemorrhaging too much, but I think we are both stubborn and refused to quit. 
Only time will tell, but even if we don't make it, I have regained trust and respect for him, which I didn't have before Christmas.