it would be nice if there were small panniers for road bikes for heel clearance. I had a small pair of panniers that were about 10"tall, 9" long and 5" wide that I gave away. For a road bike like that and carrying more than can comfortably pile on top I'd be inclined to configure two waterproof compression stuff sacks off the sides with tent and sleeping bag on top. The trick is coming up with a secure belts and suspenders method of attachment that is easy enough to remove and install without any risk of the mess coming apart while riding.
http://www.rei.com/product/768369 maybe something like this with two webbing straps and fastek buckles attaching through the loops on the bags to the rack with a final lashing of a long bungie to hold it still.
When I was young and skinny touring on road bikes I didn't take a tent, packed sleeping bag in stuff sack with extra clothes, sleeping pad and army surplus poncho on rack. Small front handle bar bag for misc. items. Kungfu slippers. No cooking gear.