For a collection of mods designed for a no-fast-travel playthrough, Geralt of Rivia's Pro Witcher 3 mod is a bit of a laugh because Geralt has never traveled faster than this. There are a few different features in the mod, like the power to swim faster than a dolphin, but the highlight is certainly the ability for Geralt to slide everywhere on his heels at lightning speed, as if the storied hexer were shredding through the world on an invisible, rocket-powered skateboard.
Brah. Sick moves.
So fast is Geralt that while sliding from place to place with the mod, you may actually arrive before the game has had time to load all the locations' models. That sounds a bit immersion breaking, but then presumably so is turning Geralt into a pro snowboarder, minus the snow and the board and the Red Bull endorsement. You can launch into some pretty sweet jumps, too.
I'm not terribly familiar with Witcher lore, but I suspect among the library of Geralt's talents, zipping around on his heels fast enough to throw sparks and leap over buildings probably isn't in the catalogue, canonically. But hey, that's what mods are for, in part: doing ridiculous stuff.