Yes NEVER bet on a bowl game early.
- Unknown injuries pop up at the last minute.
- Last minute suspensions.
- Kids decide to sit out for the draft.
- Coaching changes (if an OC leaves that can be worse than a HC leaving).
- Weather (a few years ago U Conn played a southern team in Memphis it was unseasonably cold they won big)
- Bowl trends (eg. suddenly you realize the ACC has gone 0-4 so far ATS)
I mostly avoid looking at line movement as an approach to wagering. Sometimes a key player is very questionable and the line moves one way the last day, and I suspect the line makers know that he is playing or not playing, stuff like that, but I do not let most line movements affect my selections.