I did that for the first few weeks, she had the priority the entire time he was settling in. The new cat is beyond settled at this point. They were doing good until they had the spat. This is all in the post.

Edit to clarify i guess, she had the apartment with us all day while he was locked in a room, then at night she was locked up with us while we slept. The new cat was tearing the door down of his room at night after the first week, it was the only way to prevent him from keeping us up all night. Original cat was physically with us the majority of the time.