This is a very savvy readership, so if you are already familiar with Spideroak One skip this post.
Spideroak One is an ultra-secure "Dropbox" alternative with a "zero knowledge" architecture. Your keypair is generated locally and NEVER leaves your machine. All files are encrypted (AES-256) locally before synchronizing with the Spideroak cloud. You specify the directories/file for real-time synchronization. Set it and forget it.
Of course, you'll use /dev/urandom to generate a strong password for Spideroak One. And of course, you'll store that password securely, because without it you're toast. There is no "email me a reset password" bailout.
Be sure to backup wallet.dat and zcash.conf ... because without the latter you're toast (thanks to the former being encrypted). I perform a zcash-cli z_exportwallet periodically, and I backup that directory as well.
Last but not least, Spideroak One performs complete versioning. That's potentially a game saver, as we humans have a way of mucking up a file and not realizing it until weeks later.
Absolutely no affiliation with Spideroak One, just a satisfied user for quite some years.