Some ideas to get to 160+M
1) The Switch2 will be branded as part of the Switch family like Gameboy - Gameboy Colour and simply keeps adding sales. It will run all Switch games plus 'Super' Switch games.
2) If Switch2 is branded as a new generation, introduce a Switch mini/pocket as a new affordable entry model ($100-$150) to replace the Switch lite model. With a mountain of 3DS games to port plus indie games, there will still be a lot of new content to offer going forward.
3) Switch2 does not arrive in 2024 and next year discount all the models by at least $50
That is just my 2 cents.