Do you think GTA VI will come to Series S? Because if it does, then you are actually pretty close to Switch docked target already.
I personally think they could bring it over, especially if the great rendering challenge for the game turns out to be ray tracing, which Switch 2 will have a relative advantage in due to it being NVIDIA hardware and having ray reconstruction according to Nate. It'll be at resolutions around or below 1080p docked after DLSS reconstruction, for sure, but that won't mean it can't look good still. My expectation is that Switch 2 can get current gen games more easily, but that does not mean the visuals will not be noticeably worse - and that's fine for what the Switch 2 is positioned as, being a hybrid system and all.
Whether they actually will port it is another question, of course.