Investing in heated gear doesn't make a lot of sense when living in Florida. However, we still have cold snaps from time to time and we have a tenancy to head out of state (where it may be colder) in search of better roads. I'm thinking about this very topic as I plan my trek off to North Carolina and Tennessee next week. It could be extremely warm or it could be extremely cold.
Aside from trying to avoid the real cold areas, one of my responses to cold weather is carrying base layers that are responsive to various levels of cold conditions. You may think to look to motorcycle apparel for your base layers; I looked to what the skiers wear. They wear Hot Chilly's brand base layers.
What I liked about Hot Chillys is that they characterize their products in terms of weights and offer a Warmth Advisor Scale to help you select the weights. I have a lightweight top and bottom and a mountain-weight top and bottom. Individually I've found that they cover my needs. The materials wick and they breath unlike any pair of Walmart long underwear. They're not cheap though but they work pretty good.