Well done--now leave it to them to work out and stay out of it.
DD will expect you to retract, and back down, but tell her to get packing and to make her own arrangements with her Dad for getting her stuff moved.
Stick to your guns Butterfly, and start thinking about cleaning up the room with a fresh coat of paint and renting it to a student this Fall.
You will both be much happier but don't let her talk you around to status quo. . . she's used to manipulating you like that so be preemptive and set a clear boundary