Taking a look at Nivida Orin T234: https://gadgetversus.com/graphics-card/nvidia-tegra-orin-t234-gpu-specs/
2048 Cuda cores
GPU base clock 768 MHz
GPU boost clock 1.000 MHz
TDP 50W
4000 Tflops
Samsung 8nm
Nintendo's T239 is rumored to have:
1,536 Cuda cores (75%)
unknown clocks
4-12W range
Samsung 8nm
Now the only way to get that working is either a reduction of cuda cores or very low clocks. I think we could get something around 570MHz docked which would be 4000*0,75*0,57 = 1.7 Tflops at 11W guesstimated. In mobile mode we might be looking at 330 MHz so 4000*0,75*0,33 = 1 Tflop at maybe 5W.