I actually went through something similar last year. I didn’t want to overhaul my workflow either, so I ended up using a solution that lets you mount cloud storage directly as a drive. It felt a bit like magic because my existing FTP scripts could still interact with the files like they were local. I used webdav to dropbox https://mac.eltima.com/webdav-to-dropbox/ for part of it—it allowed me to link my WebDAV-enabled server to Dropbox, so everything stayed in place while still being cloud-accessible. Took a bit of initial setup, but saved me a ton of rewriting.