For more cameras (derived from DxOMark data) see DxOMark Photographic Dynamic Range Chart. However, data on this chart, when available, is considered to be more accurate. Note that the x-axis is ISO Setting and not a "measured" value. Keep this in mind particularly when comparing to the Ideal lines. Data in tabular form is in the resizable
The Canon 6D Mark II is not much of an improvement over the original 6D and the ISO performance as a whole is inferior to the 5D mark IV. Above you have two identical crops from identical scenes both captured at 6400 ISO. The crop from the left is from the Canon 6D Mark II and the crop on the right is from the Canon 5D Mark IV.
Similarly, Bill Claff has measured the engineering dynamic range of the 6D Mark II to be 11.1 EV at the pixel level, at 12.7 at ISO 160 for the 5D Mark IV (its highest dynamic range). So those 6D II and 5D IV figures are off by a stop. The Canon 6D Mark II has a noticeably worse dynamic range than the Canon 7D Mark II. This means that you’ll capture less detail overall. That’s a big concern for landscape photographers in particular. Of course, the Canon 6D Mark II still offers a higher megapixel count than the Canon 7D Mark II (26.2 MP vs 20.2 MP).

From the Dxomark data, 6D mark ii is 0.3 stop better in ISO, 1.5 bit better in color depth, similar in dynamic range, comparing to original 6D. I took pictures for the kids, so color depth and ISO make more sense to me. I never push shadow at ISO 100, dynamic range is not important to me.

Landscape (Dynamic Range) i. 11.9. 9.6 Panasonic Lumix DMC FX150. BEST 14.8. Top score Hasselblad X1D-50c. Sports (Low-Light ISO) i. Canon EOS 6D Mark II vs Sony 0GpQ. 295 363 235 27 215 339 433 310 121

canon 6d mark ii vs 5d mark iv dynamic range