I've located an extant example. They seem incredibly rare, perhaps because they were so long that they were easily stepped on or otherwise damaged and also easily reused for other items once they went out of fashion.
Diane Thalmann, dealer in English and French antique textiles, http://www.antique-textiles.net, sold a netted one dated 1790-1795. It's looooooonnnnngggg: 120 inches by 21 inches. Heavens.
|Example of cloaks: left one is white,|
right one is black. From Gallery of Fashion
|Netted Cloak, Diane Thalmann|