Nintendo is very unlikely to be aiming at matching the performance of a current gen console, not in a portable device.
I would guess they would go for a Little.Big configuration. With 2 or 4 A78 cores. And a couple of A510 cores for the OS and background tasks.
The Orin SoC, is specifically made for the automotive industry. So it has many things that can be cut, to make a console SoC.
But it's a big chip, with 17B transistors, it's as big as the chip of a 3070 Ti , the full GA-104. And measures 392mm2.
Several things could be cut down, that are not needed on a portable console.
For example, Oring has 12 CPU cores A78AE. These could be cut to just 4. And be just A78, without the automotive instructions.
It also has a lot of tensor units for driving, resulting in 200 TOPs. This is more than a 3070, that only has 163 TOPs. Nintendo could choose to cut this figure to 80 TOPs, like a 3050.
Also has 4x 10 Gigabit Ethernet chips. The console would only need 1X 1 Gigabit Ethernet chip.
N5 is 1.84x improvement in logic density. So 17B transistors would be a bit bigger than 200mm2.
But with all that driving, AI, ethernet, etc, removed, it would go well under 200 mm2. Maybe close to 150mm2.
The Switch has an SoC that is 118mm2. If Nintendo would aim to a similar size chip, they would not need to remove many shader units.