Would you be willing to consider The Gulf Coast instead of Orlando if you are not wanting the theme parks. There are some lovely resorts, white sugar sand, plenty to do and see.
Though I haven't been in January the weather is likely to be similar to Orlando. When we have been the sea has been beautifully warm, even warm enough to tempt me in. (You would need to check for Jan>)
Many people head for St Peterersburg / Clearwater area, personally I prefer to go farther south as it tends to be a bit less commercialised, eg Venice, or Sarasota if you prefer somewhere larger. The islands off the Gulf coast are also lovely, eg Sanibel and Captiva, Long Boat Key.
Have a great time.