Why take a heavy lock that very well may be useless in most of the time? (E.g., Usually not too many sign posts in campgrounds.) You can bring a cable and small lock and teather it to your tent to achieve the same result.

Bike theft is a sport in Philadelphia. When I tour I do what I do at home rather than worry or fear: I make an assessment of the risk and take reasonable precuations. On the last three-day trip I took I never once locked my bike at the campgrounds I stayed at even though two nights I left my site for walks. Didn't feel the need because I felt the risk of it being stolen was extremely low. The camgrounds were not in denseley populated areas, and access by the general public was not easy. The three times I stopped at diners my bike was in plain sight so I didn't bother locking it up.

On the flip side, during a tour last year in Montana, a couple of times the GF and I cabled our bikes together when we left our camping areas. In one of those instances, we also hid them behind a building near our tent site. In the other, we also put our bikes inside a structure (the "shack" at the Bike Camp in Twin Bridges) rather than leaving them outside. In those cases, the camping locations were in towns and were easily accessible by passers by. The night before Twin Bridges we stayed at BLM campground and did not use the lock and never lost a minute of sleep. What were the chances that someone would drive down a 1.5 mile gravel road in the middle of the night, circle the campground looking for something to steal and try to snatch our bikes that were leaning against a picnic table 6' from our tent?