Brad Noon has the right answer. Mikes advice to make sure that the throttle body is clean is also correct.
Even under the best of conditions, the TH cure is somewhat of a compromise. I sometimes have a minute or so of cold drivability problems when the weather is cold. We don't get that much cold weather here in Southern California, but on the few days in the year that it gets close to freezing, it helps to not use too many electrical items for a block or two.
Some use two different TH plugs, one for winter with a slightly larger hole, and one for summer. It is not like it is hard to change.
