Idea

• traffic is money
• -> reduce it, don't do unnecessary reading
• mount the remote filesystem, but:
• read files only once from their online source and save the content to a local cache
• after that serve the content from the cache
• writing, of course, still is performed to the online file (you may want to monitor the effect of your website changes or whatever ...)

Example fstab entry

sshfs#login@webhoster:/htdocs/  /mnt/realmount  fuse
cachefs#/mnt/realmount          /media/website  fuse cache=/mnt/mirror