Keep in mind you have one year to use up to twelve weeks of FMLA. I don't think you can break it up, but you can save that FMAL for the most appropriate time.

If you're going to take some unpaid time, and your wife has help right now to help a baby that doesn't actually do much but sleep, it may be worth considering spending the holidays with the family, when the kid actually can focus his/her eyes on you. Share the joy of Thanksgiving through Christmas with the family, and see if you can get the little one to say "Daddy" at a few months. It won't work, but that's not what matters...