I was curious who Ohio State genuinely wanted to replace Day with so I read a thread on 11W. Unsurprisingly, there is no consensus. One poster to their credit described it well as "looking to replace a 99th percentile coach with a 100th percentile coach"
66-11 (1-4) is a home run hitter, who strikes out when it matters most. You can't just replace a home run hitter with anybody off the street and expect him to continue to hit home runs against everyone, including the one who matters most. You're going to sacrifice somewhere else.
The names they throw around are Dan Lanning (won't happen), Mike Vrabel (probably wouldn't happen and may not work even if it did), Marcus Freeman (have fun losing to Marshall and NIU and he also probably won't leave, and his rivals are down and out Stanford, USC, and Cal), and Brian Hartline, their current WR coach (massive risk).
I think Day wins a playoff game, loses in the semis, and they keep him another year.