I am currently hosting Nextcloud on Linode using the AIO Docker container. I am very happy with how this works, but the running costs is more than I would like to spend on this. I am running a 4 GB Linode (anything less would cause severe lag in the Web UI), with 2x100GB block storage (one for data and one for the Borg backup). In addition, I pay to maintain backup images of the server itself.

So I've been meaning to self-host this on a server at home instead, especially as I am looking to upgrade my media station to something more gaming friendly, freeing up a perfectly good mini-PC to host Nextcloud and other services. I've told myself that I am waiting for the Linux client of Proton Drive to arrive, so that I can utilize my 500 GB storage there to keep a synced copy of the Borg backup repo. I am not sure I am willing to wait for this anymore (who knows when that will be ready?), and thought that maybe something like filen.io could be used in the mean-time, as I could get 200 GB there for €2/month. But I am open to other solutions as well.

So here's the actual question: how would I best make sure I keep the backup repo safe so that I could restore it later if something went wrong? What would the ideal setup look like, including local and remote copies?