It should be noted that the inn is right next to Krasus' Landing. As such, if one is a proficient flyer, they may be able to swoop into the inn before the guards notice the illegal use of a flyer (most of Dalaran is a no-fly zone). In fact, if a member of the Alliance is fast enough, they could zoom right into the inn past the guards. As long as no Horde alert the guards, they should be able to remain in the inn and have some of the feast on the tables!