I always include the night before, incase I want to do a late night drive, and we'll still get in early enough to set up camp and get some sleep. Which also might be good incase you get a head start or get farther than you plan to on your drive. If not we just sleep at the rest stop on I-95 a few miles south of 192. But since we're still staying for two nights, we don't incure any penelties, as long as you cancel it during the day. Now if we cancel completly we'd lose one night's stay. I've actually canceled the first night at about 9pm when my dog got sick on the way up there. She kept throwing up and so we spent about 2 hrs at a hess station waiting for her to feel better. We didn't get up there till about 3am.
I've stayed in all the loops so far, p/h-up - 2000 loop, f/h-up - 1600 loop (pet), and prefered - 300 loop (pet). The full hook-up sites were by far the biggest, seemed even bigger than the prefered loop, which is good if you're camping and have two tents, or even if you have a small camper and plan to set up an extra screen porch area. Now the preffered loops are much closer to the settlement but even at the 300 loop it's a bit farther than what I would want to walk, so we always hopped on the bus. All loops have the problem of the few sites that seem to be so far away from the stupid comfort station and the last few stays, I feel like I've gotten those few sites.
Unless reserving for a major weekend, you shouldn't have a problem getting a site.
Now if you're travelling with a dog, prefered and full sites have dog loops but I don't think partial sites have one, but you still have to pay an extra 5$ a night.
BTW, Janurary is plenty early, our ressie is generally made only a couple weeks in advance. There are most sites at Fort Wilderness, than any hotel, so it shouldn't be difficult to get to site 5 months in advance. The only thing I could think of is if you're planning on staying for more than a month, which some snowbirds do.
