It's not too early to try a triathlon. Although the lakes may be close to freezing, there are several local indoor triathlons to choose from. Indoor triathlons are held in workout facilities and consist of a pool swim, the use of an exercise bike, and a run on either a treadmill or indoor track.
If you are new to triathlon, they are a great way to practice what you've been training. If you have more experience, you can challenge some of your buddies and have fun with a bit of smacktalk while determining the "Ruler of January"