Peak draw is not the same thing as sustained average. My 1070Ti can peak at 250 watts, but with the A/F curve set in afterburner, averages 180.According to the TPU GPU DB: "Being a triple-slot card, the NVIDIA GeForce RTX 4090 Ti draws power from 2x 16-pin power connectors, with power draw rated at 600 W maximum."
600 Watts isn't that much more than what 4090's can draw now. My 4090, when playing Dishonored 2 at maxed DSR resolution, posted the following peak power draw stats:
"aftrbrner: 574.9 Watts, GPU 16-pin HVPWR power max.: 551.2 Watts, GPU PCIe +12V Input Power max.: 15.6W"
Anyways as for the 4090Ti "cancellation" Nvidia is not selling anywhere near enough 4090s and even less 4080s. I will bet hard $$$ that the slow high end sales is why the 5000s is "delayed until 2025" and the 4090Ti is "cancelled"