It's fairly possible they do exist. Little does Tolkien speak of Forodwaith. Men living there only appear in the appendix, the ones that help Arvedui. Besides, Angband was said to be very near the cold north of Middle-earth. So it is possible that after the fall of Angband after the War of Wrath, many of his servants would flee to where the Valar and the elves and men would not follow: the far and frozen reaches of Middle-earth.—Unsigned comment by Danilo (talk • contribs).
The section detailing their portrayal in adaptions needs to be updated to account for the video game The Lord of the Rings: War in the North.