To me the most logical thing would be to just use HDMI-over USB-C.
If you have a "Power Dock" then it necessitates a protocol for communicating with the dock's GPU (and maybe CPU), but the USB spec basically gives Nintendo and Nvidia free reign to create their own proprietary alt-mode if they deem it necessary. No matter what, with a "Power Dock" the dock would handle the video out to TV so there's no need to pass a video stream through the USB connection while all the computing is going on.
If you have a "Power Dock" then it necessitates a protocol for communicating with the dock's GPU (and maybe CPU), but the USB spec basically gives Nintendo and Nvidia free reign to create their own proprietary alt-mode if they deem it necessary. No matter what, with a "Power Dock" the dock would handle the video out to TV so there's no need to pass a video stream through the USB connection while all the computing is going on.