All the black outfits

Well they certainly won’t have to dash down to Marks ….

They must have the black clothes on hand for public occasions. Like the official hearse and the golden coach these things must be at hand when needed.

I suppose we will never know what conversations princesses have with their dressers when one of the princess's relations is obviously in failing health.

I expect they have outfits from previous years which have been speedily adapted, and their bespoke tailors can whip something up quickly.
I wonder more about ordinary people, wives of dignitaries, for example who suddenly have to wear a black hat at very short notice.
One well-known tie manufacturer has suspended making normal ties to meet the sudden demand for black ties.

Hardly difficult for them to have instant access to clothes…or anything !