You will not find a lot of posters returning to the Forum after they have reconciled because they are busy focusing on the hard work of reconciling. Some do return and they are the ones that have taken the time to return to post snippets of how things are going.
Now, the other side of the coin is that some do reconcile and then years later discover that it's not working out and then separate and divorce. I have several friends from this forum who have done this. Sometimes the MLCing spouse returns and their personality is the same, others return and keep some of the traits that they picked up during their tunnel time and others are completely different. Some return even better, but the bottom line is that no one can predict how they will come out of the MLC oven. As for how long it takes, it takes as long as it takes and sometimes they want to return home before they are finished w/their crisis and eventually, they jump start their crisis again and usually it is far worse than the first time around.
Some take 3, 5 or even 7 years and others could take longer, depending upon the person, their issues and their personalities and yes, others may remain stuck until the day they pass away.
I know you are looking for hope and that's okay. It's good to hope and have faith that he will return home. We all come here searching for success stories, but the bottom line is that no matter what happens, you can't control the outcome of his crisis. You didn't break him therefore you can't fix him. However, you can control how you deal w/him during this time. Have compassion for what he's going through, but that doesn't mean you come a doormat, be civil to him and above all else, dig deeper for patience. You can keep the door ajar for as long as you need to, but again, do not allow him to walk all over you. Keep a close eye on your financials and bank accounts. Seek the advice of a good lawyer just so that you are aware of what your rights are. Do not share that info w/him and do not share what you learn along the way from reading about MLC and especially this forum.
Try to keep the focus on you. You need to find a way to keep strong, learn all you can about MLC, and take care of yourself, i.e., mentally, physically and emotionally. Come here to ask questions and vent. There is always someone around to post to you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.