Surely no room to store one of those huge dresses if you live in a caravan? The caravans we've seen all seem to be remarkably clutter-free IMO (unless they just shove it all up one end & then film the other end 
But anyway...
Also not everyone can be loaded so is there a market for 2nd hand wedding dresses, I wonder? What if someone has several DDs, & can't afford £20k dresses (plus bridesmaids etc) for all of them?