I bought about such a setup 2 months ago, drn 8700k on the Maximus X MoBo, Geforce GTX 1080 Ti OC and 16GB RAM.
I run the whole thing on the BeQuiet DarkPower Pro 11 - 650W power supply.
Even with OC, I never got above 550W under full load! In gaming mode approx. 400W.

In my opinion, the DarkPower Pro with 1000W is a bit exaggerated, unless you want to use a multi GPU.
It is recommended to run the power supplies at about 50 - 75% load to achieve a good efficiency.

I recommend online calculators for power requirements for such questions, e.g. the one from be quiet! https://www.bequiet.com/de...
They don't have the i7 8700K in the list yet, but with a 6950X (which has a higher TDP than the 8700K), 1080Ti and overclocking, they come to just over 500W. So 1000W is rather overkill.