Soundwave on 21 October 2016
I think NS XL would probably be the easiest.
A micro or smaller NS is largely going to depend on 10nm or 7nm manufacturing processes becoming available *AND* cheap (Nintendo hates eating lost costs on wafer losses), that will happen, but a NS XL is something they could make right now if they really wanted to.
A "NS TV" with no LCD display/battery would also probably make some sense but I don't think Nintendo wants to release that any time soon because it undercuts the message of NS being a portable console.
