If you have 100GB+ with Google, takeout doesn't work. Either you have to manually download files 2GB at a time reauthenticating each time, or try a 50GB download the times out on the server side as gets cancelled with auth error. There's no way to but a physical backup or run a long running process to fetch your data reliably over the course of the week.

It might work if you get an GCE VM and crossload your Google takeout to cloud storage and then download using cloud storage APIs.

Looking at the choices on that takeout page, I realized that there were a number of Google services I didn't event know about: "Google Arts & Culture", "Crisis User Reports", "Handsfree", "Textcube".