How will custody be for our twins if we are separated and we used a surrogate?

My wife and I recently separated. It was her decision. Neither of us has filed for divorce or custody at this point. Her sister is our surrogate. We used my sperm and we received a donated egg that is neither her sisters or hers. My wife decided that she was going to live somewhere else and has been out of the house for 5 months. Our surrogate is due in August. My wife refuses to come home even when the babies (twins) are born. She wants to move into a friend's house or get her own place in a city that's close by. I want our home to be the babies home until they are at least 10 months old and a little stronger so we don't have to transport them so much. We have had all the paperwork done by an experienced attorney as far as the surrogacy is concerned. The paperwork states that my wife and I are considered the legal parents as soon as our surrogate gives birth. My question is below: If my wife refuses to come home and decides to move somewhere else in a safe environment and wants to split custody 50/50 but I want the home to be the babies and her and I can rotate, what are the options? If we have no legal agreements as far as custody and/or divorce at the time of birth then who says where the babies will go that day, or that week, etc? This may not matter but the surrogate, and all the in-laws are on my side and will fight for the babies to stay at our home and her and I rotate. Will a judge say that it's not healthy and/or safe to be transporting 2 newborns back and forth every few days? My wife and I are on pretty good terms at the moment and I'm afraid that if I fight too much to keep them at home then it may not be pleasant for much longer. We already agree on bills, the house, money, and even allowing each other to see the babies even on the days off.