I live about 1.5 hours east of you in Crestview, FL. I've successfully used sleeping bags in my hammock when the temps were in the 20's. That said, everytime I've done it, my bags were rated at 0. My top and sides were fine but I was able to feel a chill wherever the bag was compressed. A CCF inside the pad mitigated some of that chill but really constricted any movement.
Anything below about 65 degrees, I would highly recommend using something under the hammock. I have used old sleeping bags that I've hacked up and turned into UQ's & PLUQs. I recently made a down UQ that should be good to near 0--might only get to use it once or twice a year though.
For this neck of the woods, to be comfortable hanging 95% of the year, I would recommend a PLUQ and then something to get you to around 40. Supplement those with about a 40 degree TQ and with proper clothing you should be set for this area.
As an aside, another forum member, Buffalo Skipper, is in Pensacola and has amassed quite a varied collection of quilts. You might want to PM him for advice/lessons-learned.
What I can tell you from my personal experience is that once you use a UQ, you'll probably never want to be without one ever again. They make that much of a difference.