There has been some discussion about a Nintendo Switch Mini coming in the future, when Nintendo is able to get smaller, cooler Tegra chips from Nvidia that will allow Nintendo to construct a smaller more portable Nintendo Switch that can handle the heat constraints of this powerful system.
However, it is possible Nintendo will want to have something to market sooner, in order to compliment Pokemon if it launches this year.
Something that can entice long term fans of the series that are used to playing the game on more portable systems.
One possible way to cater to those fans in a timely manner, would be to make a Clamshell revision to the Nintendo Switch (a la Nintendo Switch SP).
As you can see, a clamshell design (with the same size screen and same height of joy-con) would actually provide more space for heat dispersion (spacing the battery away from the Tegra X1), and may actually be possible to house a slightly larger battery as well.
If this revision replaced the X1 chip with a X2 chip, the battery life could be extended even further to really leverage benefit to people looking to game on the go even longer without bringing a battery pack.