Welcome to the land of MLC. You've pretty much answered your own question. If you are asking when to give up, then you aren't there yet. Many LBS move on and when they move on, some of the MLCers will notice and begin reaching out to them. Each situation is different, but I can promise you this...you will know when you've had enough and will be ready to move on.
Each MLC is different because of the childhood issues, personality and environment of the person in crisis, some stay in crisis a short period of time, others longer and then there are those that remain in crisis until they die. No one can predict who will survive and how long they will be in crisis. That's why it is important to keep the focus on you, your family and your life. Live your life to the fullest as if they may not return.
It's been said many times, the divorce decree is just a piece of paper and some do remarry and go on and have happy and productive lives. Ultimately, the LBS is the one that determines whether to shut the door, move on or reconcile...but that's far, far down the road.
For now, detach, keep the focus on you and live your life.
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.
