I'll answer a couple things here at once.
No ice on site, I'm still amazed no Boy Scout troop has tried to do ice on golf carts but you'll have to hit Publix or gas station. Water, well you can fill at the comfort station in the shower is a tap but I would bring some.
As for your camping options, the lower area is out. I've marked up the new reserved spots along the road, Esses Overlook on your map yup it's named now. The upper spot MIGHT work but it is not close to flat and the flat areas have campers on them who are there every year. You can't drive anywhere close to it and up in the tree line is the levelish areas.
Comfort station is green circle at lower right. Our camping area is orange circle at lower left, we have the lower side of the tree from the map, Tom's kids have the upper side. He had not missed a major event at the track since it opened until he passed last spring so it will always be his site to me.