You
might be able to go
slightly smaller, but you wouldn’t really be able to get any smaller than
@Shank did. Even then, with the dimensions that
@Jonut521 gave, you
could not fit a Wii, portable or no, into that sharpener.
You’d need to fit an OMEGA trim inside of it. You’d also need power management, even with an external charger, and U-AMP if you want sound. You‘d also need to put in a GC port or IR sensor, for controlling stuff, and if you used IR, you’d also need to relocate Bluetooth. Even without a screen, you’d still need a video port of some kind, though granted, that is smaller than a screen.
All in all, you can make the Wii smaller than anybody ever thought possible when they made it, but you unfortunately won’t be able to fit it inside that sharpener. It‘d certainly be cool if you could, though.