When should I apply for On Base Housing?

I am currently attending college and will graduate in the spring. I am in ROTC and will be sent to Advance Camp in June as an at Camp Commissioning. My fiance is an E3 in the Marines and in BRC. He will be sent to his unit in March. (He already knows we're going to Camp Lejeune.) There is currently a 3-month waitlist. We have a tight timeline. In May I graduate the 12th in Texas, the wedding is the 14th in South Carolina, and we're moving the 16th from Texas to North Carolina. Should I apply in March when he has orders and provide May as the expected date for housing?