Big Life Decision

So, it's been a while since I posted, but things have been going very well.I am a father who fought for a while for 50/50 rights to my recently 2 year old boy and my son's mother and I now get along like gangbusters and are actually very good friends and amazing co-parents. It took a lot of work on ourselves, but we did it and life is grand.A little about his mom. She's a single mom of five. Four from her only marriage and then our son. She is a super mom. Her life is about those kids. She is able to work, do on-line schooling and still be a full-time mom. Her drive and motivation are insane and her children live a life that would be the envy of parents with a single child. I have nothing bad to say about her as a mom. The only thing that is a negative is her family. Her family is toxic. The use, drain and stress non-stop. Somehow, despite it all she keeps it all afloat is is a model mother.Her ex however is simply the worst. Unreliable, impatient, lies, manipulates, never has money and often struggles to care for her kids. Sometimes to the point where he doesn't even have food for his two weekends a month. He seems to go out of his way to make life as hard as he can for her. He fills his kids' heads against their mother (thankfully they are all getting old enough to see the lies) makes plans and then flakes, shows up to disrupt when he knows she has plans. It's awful to watch. It gets worse and worse by the day and it is beginning to take it's toll on her.Every choice I make I always consider what's best for my son...Today she dropped a bomb on me.Come summer she wants to pack up and go. Move to a larger city where she has some great support and is far away from her ex. Several hours away.She told me that she is more than confident in me as a father and knows that my son would have a great life. She has told me she is willing to give me full custody and be a holiday mom. If you knew her you would know the weight that statement carries. For her and myself...I'm more than able to accommodate this. That wouldn't be a problem in the least. What concerns me is that I don't know if this is best for him. He is a super smart boy. Having four siblings to learn from has really pushed his development. He loves his siblings. Loves his life. I just don't know if this would be the best for him...I know that he would have a great life in our city, but the fact is that if his mom stays here the other children suffer. It may not have worked between us, but I love the other four as much as my own. They deserve the best and I would never stand in the way of that. I know it's best she goes, but I just don't know if I accept her offer and split our son from the rest. I'm not a selfish man. I would suffer and miss my baby boy if I had to. It's not about me. I only care about what's best for him.I would eventually move, but I am currently on a career trajectory that would not allow for me to do so for a minimum of two years, and that's if I go balls out and push as hard as I can.I have no frame of reference to draw from, no idea of consequences for my son or the other children and no idea where to begin.Any input guys? via /r/Parenting http://ift.tt/2iKQfrp