Well, I haven't put much thought into this lately as I'm still waiting for my bandwidth upgrade. My reasoning follows pretty much along the lines you laid out in your posting. Apart from theft and/or vandalism, I'm looking at a somewhat volatile environment that, as a worst-case scenario, will leave me with total equipment loss. One of the third-party providers I'm working with offers a distributed storage solution based on Ceph (can't post URL here), with a POSIX-compliant file system layer on top. According to their tech support, I will be able to NFS-mount zoneminder's 'events' directory against their service. Throw in a 'decoupled' (ie, remote) zoneminder DB, and I should have a decent restore point if things go south -- provided my upstream doesn't get chewed up in the process, of course

Apologies for not being more helpful at this point, but I'm still waiting for Verizon to play ball. Please do keep us posted if you find out more.
Bests, Mike