1Heat coals or gas grill for direct heat. Place potatoes on 30x18-inch piece of heavy-duty foil. Sprinkle with salt. Dot with butter. Sprinkle with cheese and bacon chips.
2Wrap foil securely around potatoes; pierce top of foil once or twice with fork to vent steam. Cover and grill foil packet, seam side up, 4 to 6 inches from medium heat 45 to 60 minutes or until potatoes are tender. Sprinkle with onions.