We also really like to camp in the "cooler" weather of late fall and early winter - when the temps are in the 30s and 40s during the day and down into the 20s at night.
If we have already winterized, we will unwinterize when we get on-site and then winterize again before we leave the campground. I want the water for the toilet and the kitchen sink, but we will normally use the bath house for showers.
We make sure that we unhook the hose from the spigot in late evening (we keep a couple gallons of flushing water in the bathroom) and we hook the water back up in the mornings when the sun hits the spigot and/or it gets above freezing.
A big fire in the evenings with friends is wonderful, but I usually have a blanket as well as a jacket and hat, maybe even gloves.