Crashplan is smart enough to deduplicate so if you are just moving files around, they won't be resent. Even if they are changed slightly only the differences need to be sent.

Not sure on BackBlaze whether it does parts of files or just whole ones, but the technology absolutely exists.

As for 111 days I think my initial backup was about 100 days but I just let it chug along, prioritising certain folders first. Once that was done I added more less important stuff and just let it chug along in the "background". It got there eventually.

I'm a big believer in automation of backups. If you have the resolve to manually do your rotation etc, great.