[diakritikal]

Can't you just schedule an rclone cron job? http://rclone.org/ - it supports a decent number of cloud services, maybe one suits your budget/requirtements? That's what I do from my FreeNAS box.

[leesalminen]

I just configured rclone to sync roughly 1MM files (and growing) to GCloud Coldline. Excellent tool.

[hyperion2010]

Having looked around a bit now that seems like what I will end up doing.