I was a Mum who went home while my bub stayed in SCN. I was allowed to stay for 4 nights. I then travelled 30 minutes each day to see my boy. I would express at home at night so they had milk for the following night. I would also express after my day feeds as he was being topped up after I fed him. It also meant there was extra for night. I was allowed a "rooming in" night on DS1's last night in hospital.
Every hospital and every situation is different. You'll need to take it as it comes. Hopefully you'll get to stay.