While away in the UK I've never had a problem fiding somewhere to unload and reload DDS. (I also use single darkslide 9sx12 plate/film holders).

Usually I can use a hotel bathroom, or climb into a cupboard , if all fails I ask in a Real Ale Pub if I can use their cellar - last time I did that in the wilds of North Yorkshire it transpired that the land-lady had used 5x4 herself and studied with Chris Killip