A four-foot bolt cutter will make short work of pretty much any chain, even a Kryptonite New York, and professional bike thieves know what tools they need. IMO, the closer you are to an urban center, the less you can afford to compromise.

(My own unwillingness to compromise makes things simple: If my bike can't come in, neither can I. I never lock my bike outside anywhere, ever.)

I think the U-Lock + cable is still probably the best strategy, combined with riding an ugly, unattractive bike if you have to leave it outside.

RichC