Ahhh...PROM! I encountered that today. After my dress fitting I went over the tux rental place to meet FI. As soon as I walked in the door I was overwhelmed with hormone driven teen boys in line for their tuxes...lol! The line went from the back counter to the door! I stepped out and called FI to tell him we are in the PROM twighlight zone and we need to reschedule.
I'm sure everything will work out. You have plenty of time to get all in order.