For the people talking about cart sizes, let's look at previous generations.
GBA, maximum 32mb
DS, 8-512mb (1/4-16x previous gen)
3DS, 128mb-8gb (1/4-16x previous gen)
If NX follows that same pattern than it will have came carts ranging from 2gb to 128gb. 128gb isn't necessary not but maybe in a few years once PS5/XB4 release, Nintendo may need that size carts.
Also some of u are getting too hung up on AAA western 3rd party titles which is something that has never really been a big mover of Nintendo hardware. The primary support will likely be Nintendo published titles, Japanese 3rd parties, indies, family friendly western titles.
The majority of games will probably be 32gb or under.