For website planning, you might also consider http://www.rvparkreviews.com. Click on the US map on the state you might be interested in, then keep clicking to drill down to the specific area of the state to get a map of individual parks. It has what I consider to be the most reliable reviews and ratings since they come from individual campers.
Good luck on the reservations. I had trouble in the November, 2016 time frame for the Kentucky/Tennessee area, but was successful with a good bit of calling. You might catch a cancellation with persistence.
