Here are my recommendations:
Cardinal Center Campground - Marengo. 35mi north of downtown, exit 140/Rt 61 . Huge campground right next to freeway. Easy on/off of I-71.
Cross Creek Camping Resort - Delaware. 26 miles north of downtown, exit 131/Rts 36 & 37. About 4 miles west of I-71 exit. Large campground across from Alum Creek State Park (next listing). There's a Cracker Barrel, McD's & several other fast foods at this exit on the west side of I-71. Also a Flying J with a Denny's & Pilot travel centers on the east side of I-71, if ya need fuel/propane (or a free place to overnite). See photos in my album (link in sig)
Alum Creek State Park - Delaware. 26 miles north of downtown, exit 131/Rts 36 & 37. Large state park, sites have good privacy, developed when campers were smaller so not big-rig friendly. But since I see you've got a truck camper, you'd fit in just fine. See photos in my album (link in sig).
P.S. Don't go through Columbus on I-71 if you don't like traffic & avoid at all costs during rush hours. Take the outerbelt (I-270) either east or west to go around.
Lori-