Can an 11-Year-Old Bikepack 80 Miles? (Fort Belvoir Tour)

Weekend tour with my son using mostly rail trails or bike trails along 40 miles each way to Fort Belvoir Travel Camp. https://www.novaparks.com/parks/washi... https://www.fairfaxcounty.gov/parks/t... https://www.traillink.com/trail/fairf... GLDRGNQXYE6YNDSH