Changed our van some time ago to one with wardrobe in shower room and haven't noticed clothes being effected at all. Always make sure roof vent is open and, if possible open window as well.
I have put Penny Vents into the wardrobe, 2 top and 2 bottom. These vent into the space between the back of the wardrobe and the back of the van where there is a 4" wide void.
Ours is in the bathroom and our clothes don't get damp. We do use our shower daily, opening Windows etc. In fact having your clean clothes to hand when you get out of the shower makes perfect sense when you think about it. You have everything you need to hand.
------------- Im no cactus expert, but I know a prick when I see one!
Only used a shower in a caravan once. Too much of a carryon !. and the thought of all that water and steam inside a caravan doesn't bear thinking about !