We could easily spend $5K after the statement period closes in Dec. This would be $5K we wouldn't have to spend in 2019 to get the CP, and in addition we would get the miles.

Spending after the statement closes in December risks that the 25K bonus hits in 2018 (if Visa issues an additional statement), and not spending in December risks that we fall $5K short of the remaining $85 K needed to get the CP. It is easier to get to $110K if you have 12 full months to do it rather than 11.