Does the car ever get taken out on a nice long highway drive? I have a car that sees similar driving conditions, but once a week or so it also gets out on the highway for about 45 minutes as I drive to see friends or visit my sister. That helps to get the oil up to temps to help get any moisture out.
Others who know more then me will come along and comment, but I think you're fine. Using conventional you can get a quality 5w-XX (what's the vehicle spec'ed for?) that will give you good cold flow in the Georgia winters, and still give you excellent protection. In fact since it's a Ford and is probably spec'ed for 5w-20 (please correct me if I'm wrong), why not go with Motorcraft 5w-20 semi-synthetic? It's a semi-synthetic, it's got good cold flow, it has shown to offer excellent protection, and the price is better then some conventional oils. It's really a win-win for someone needing a 5w-20 in your situation. It's also offered in 5w-30 and other weights, but the 5w-20 is the only one I've seen in large containers.
If it was my vehicle, I'd use Motorcraft and I would sleep easy at night knowing the engine is protected and can handle the cold starts fine.
As for the OCI it depends on how the car is driven, if it ever gets up to temps, etc. Does the vehicle have an oil life monitor? If it does I'd use Motorcraft and would just follow that
