@[email protected] Remote backups might be rough with that upload speed. For example, you will be looking at over 2 hours per GiB uploaded.
I personally have a 3 node setup using kubernetes and I run longhorn for volume management. I do hourly snapshots, and then daily backups of all volumes to an additional drive on one of my 3 nodes with a simple NFS server which is also running in kubernetes. In longhorn I keep 2 replicas of every volume as well so losing one doesn't hurt anything.
I would imagine it would be pretty easy in this case to replace my local NFS with AWS storage and then I would have remote backups, but since I back up roughly 100 GiB per day that would be a little time consuming. At my 50 Mbps that's about 4.5 hours, though remote backups could be done less often as a last resort backup.
I use LibreOffice Calc a lot for work when I'm required to deal with xlsx or csv files from our customers. For most other things, Google Docs has us covered so employees can collaborate. For me it's less about FOSS in this case and more about using the tools that best fit our needs for any given job. If I didn't have something that worked as well as LibreOffice does, I would be forced to use Windows for work.