RickC,
Another thing to keep in mind before bottling is that while the oak may mellow a bit, it is possible that it will not mellow enough for your taste. You then have the option of blending a wine that is either a) not oaked, or b) lightly oaked together with this wine in question which has too much oak for your taste. Keep this in mind as an option but I would not recommend doing this right away. If you are going to be bulk aging this wine for months more, you have the flexbility of time to help determine if the oak softens to a point where you satisfied.
If you are using oak additives other than a barrel, it's likely a prudent decision to err on the lighter side and add less than you think you need. Having half the cubes in the wine for twice the time will give you more control than all of the cubes at once. It can also spread your oak over a couple of batches, keeping per-bottle costs down.It's much easier to add a little more oak flavor than it is to take itaway after the fact.
- Jim