I think some of you guys are underestimating the new gen consoles a bit. Sure, they don't have the best video card, but the biggest impediment to large mods is usually RAM/VRAM, of which the consoles have a reasonable amount--8GB shared between the CPU and GPU. Skyrim never addressed more than 4GB of RAM, and a 2GB video card was enough to handle the game even with graphic overhaul mods. An Xbox1 or PS4 still has another 2GB to spare.
I'm sure a mod that replaced every texture with a 4K version wouldn't fly, but texture replacers or new object models that are similar in memory load to existing game assets should be fine.