Nordhouse Dunes would be a good place to hike and backpack in. No RV's though. Could RV at Lake Michigan Recreation area (no electricity, no water at site, almost 100% shade) at north boundary or Ludington State Park (water, electrical, fairly open) on south boundary. Below is the link to wilderness area map and info.
https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5151641.pdf