The invasion of Kyushu was expected to cause anywhere from 70,000 to 766,000 allied casualties, rising to 1.7-4 million if the Japanese populace fought en mass. It is likely that these figures are too low, cobsidering the allies underestimated Japanese troop strength. It would take an estimated 120 days to break through the 900,000 defenders.
With this in mind, would invading Hokkaido be a better option? The allies would have 2-3 infantry divisions opposing them, compared to 14 divisions, 3 tank brigades, and various other units on Kyushu. The defenders on Hokkaido were also oriented north against a potential Russian invasion, leaving the southern beaches undefended.
If the allies go for Hokkaido, they can attack in spring 1945, giving them time to build up for an invasion of Honshu in the fall of 1945.
So, what do you think? I'm especially curious to see how Hokkaido would compare to Kyushu as a staging point for CORONET.