changing rooms within a magical gathering

[stitchfan18]

DF and I are getting married during our Magical Gathering this August. We're booked in two different rooms since DF will be staying with his groomsmen before the wedding, but after the wedding obviously we'll be stay together. I'm not so worried about room keys as I am about having to deal with 2 different room keys and the DDP. Should we just switch him in into our room since the majority of our stay will be after the wedding? Also, can we do this when we check in, or do we need to call ahead and get it changed?
Thanks