I don't know how many days it's been since I started cutting back on the caff, but I'm pleased to report it's been a success: as of about a week and a half ago, I'm running on about 75 mg a day.
This the equivalent of
1. a small Starbucks espresso drink, like a Caramel Brulee Latte (yum for holiday drinks; Brad loves the Peppermint Mocha), or
2. (my preference) a medium half-caff espresso drink (i.e., one shot of regular espresso and one shot of decaf) such as an iced Caramel Machiatto with whipped cream, or
3. a can of Mt. Dew + 2/3 of a can of Coke later in the day (I throw the rest out or give it to Shannon)
So, the basic gist is that you can get control over your caffeination with a minimum of discomfort and sleepiness - if you're willing to put in a few weeks of effort and really be conscientious.