I don't think it will happen in the near future, but something similar to a Chromecast could eventually become a new form factor. Think something like the current Switch, but it would be split into 3 parts: the Joycons, the tablet screen and the tablet processor unit (the Chromecast-like thing). By default they all come attached to each other (but not hanging like Chromecast, more like an cartridge-like thing that is inserted into the tablet), but you can detach them all, leave the screen at your home and bring only the processor and Joycons with you, then connect the processor to your phone or some other screen to play it.