Joycons look to be about 4" wide. SNES controller was about 5" wide. The original Gameboy was about 3.8" wide.
Which begs the question - was the SNES controller or Gameboy that uncomfortable to hold? Not perfect - but not the worst from what I remember. Certainly bearable when the game is really good...
I predict NX launches in 2017 - not 2016