If they can hit
30 million NX consoles
55-60 million NX portables
Assuming a tiered hardware family like above ... I think Nintendo would take that and run.
They're probably never going to be the market leader again but if they can maintain a userbase in that range, that would be a healthy amount to make a decent profit factoring in also money from the smartphone business and licensing opportunities.
But they seriously need to step up their console game, going from 14 million Wii Us to more than double that with NX will not be easy.
Japan must remain portable crazy too, that's going to be the crux of the portable market going forward with Europe and North American kids gone smartphone crazy.