Dream Game

So this is a long shot, but hey, miracles are possible.

The other night, I had this really awesome dream where I was playing a game that doesn't exist. The setting was a cross between The Witcher 3 and Skyrim (Medieval Nordic villages and cities, high fantasy, dragons, etc.). It had base-building/survival mechanics like Fallout 4, and parkour traversal/stealth mechanics like Assassin's Creed. There were missions spread out on an open world map. When I woke up, I was disappointed it wasn't real.

I was just wondering if such a game actually exists, or any games close enough that included as many of these elements as possible (the stealth and base-building in particular). Thank you in advance!