Definitely need a proper backup system or at least faster Internet. This is my workaround for moving my ownCloud instance to my new VPS (the data itself is backed up locally on several machines but my upload is only 20MB so it would take ages).

Tar it, split the tar into 10GB files to get around a file size limitation, then copy the files to OneDrive with rclone. Then copy them back and re-assemble them (hopefully, as I say the actual data is backed up as well).

(a clip of a terminal showing a listing of files split from an archive called cloud.tar.lz4 that are being restored to a directory using pv, tar and lz4)