Modder Starac/Ancient has released a new version of his graphics/texture overhaul mod for The Elder Scrolls V: Skyrim. This new version adds some new 2K/4K textures, though the modder did not specify which are the new textures that have been added.
Source: N4G PC Skyrim Realistic Overhaul features 10GB and more than 1500 of high quality 2K/4K textures