Let me put it out there. I don't agree with Ahsanford view of the 6D / 6DMKII.
a. The Canon 6D aside from the sensor and 2AF points was essentially technology from the 5D MKII with wif-fi & gps thrown in. The cost to Canon was not a ground up fully fledged price and they had wriggle room which saw the price come down to attract people into FF and more expensive glass.
b. The 6D MKII could be introduced at a higher price point, in the UK the 6D sells for £ 1,449 body only, the 5DS £ 2,799, the 5DSr £ 2,999 and the 5 D MKIV 3,499. Gaps of £ 1,450 (double), £ 1,650 and £ 2,050.
The 6D is part metal body with weather sealing similar to the 80D, I do not see that changing and maybe getting better. With the specs. I outlined earlier Canon can keep the product differentiation from the 5D MKIV, improve the camera over the current 6D and leave room for a "rebel style" entry level FF camera and have a line that mirrors the 7D MKII, 80D and 77D in the 5DIV, 6D MKII & the 8D (Rebel entry level). The 1D series really is in a level of its own and not directly comparable.
The Canon CEO talked about more variation but longer replacement cycles this would fit with that. Equally Canon puts the current 6D in the middle of its range of cameras not at the bottom as entry level so this still fits that criteria.