"Or you can scrub your laptop clean, storing everything on an external hard drive that you leave at home. Then you know you are safe from prying authorities, at least at the border." That is unless you believe that those prying authorities have the will and the way to leave an undetectable backdoor in your laptop. Breaking the chain of custody in any laptop today is akin to destruction of trust in that device. Who is…
Rather than leaving it at home, a trusted third-party service could supply a image/reimaging service at popular travel endpoints.
A lot of risk in it I suppose.