We moved Grif to a big bed at 12 months and shut the door. A gate didn't work for us because he shared a room with Brayton and:
1. Brayton needed to get out of the room during the night to potty.
2. Brayton needed to get out of the room in the morning and not wake up Griffin or me.
3. Griffin is a super light sleeper, and if the door was open too much noise was coming in the room.
4. Griffin could climb over the gate we had anyway.
When Griffin would wake up, he would knock on the door (and by knock I mean beat on it with his head and kick it
) and we would come let him out. When he learned how to open door knobs, we moved him to his own room and put a child lock on the inside of the door. He still knocks when he is ready to get up.
I think if Griffin wasn't such a monkey we would have just used a gate.