Well, no longer.
Cryptic announced this past week that a new fashion bag is on its way to the game for the upcoming Lost City of Omu module. The fashion bag will be added to the inventory window and will start out with 24 slots for outfits. This limit can be expanded for Zen, of course. And it should go without saying, but only fashion items can be thrown into this bag. No trying to stuff a horse into it; he will just say, “Neighh.”
Source: Neverwinter