when i have been too busy to get to a wine that was on the back burner i have added oak over a year+ after fermentation has stopped, i agree that chips are your best tact because of speed of delivery and speaking of chips if you ever have a wine that you felt needed degassing ( rare w grapes but it can happen) and you added the oak and decided to be "on the ball" and degas during your time when the oak you applied is delivering the oak....do not yield to that "need to be on the ball" i have seen degassing cause the oak chips and cubes to sink to the bottom...oak chips especially fall on each other at the bottom and the oak does not leach into the wine...always always either degas 100% before applying oak, or wait until oak has done all you asked of it