IFTTT has a trigger to upload all new photos from Camera Roll to, say, Google Drive. But it can't delete them from Google Drive automatically (as in a trigger "every photo deleted from Camera Roll, delete from Google Drive").
A little workaround I do (so I don't have EVERY photo uploaded to my Google Drive) is to have the trigger: "every photo added to Album 'Keep' upload to Google Drive." This way only the photos that I think are truly worth keeping get uploaded. Then I periodically clean out my entire Camera Roll, knowing all my "keeps" are backed up.
I hope IFTTT adds support for Mega soon, as then an additional 50GB of free "cloud" storage would available!