Upgraded my VPS (which this runs on) to a newer ubuntu LTS – this was suprisingly simple. My database is hosted elsewhere so that was a non issue (I need to do a test of the migration process at some point). As such all I needed to do was copy /var/www and /etc/ (though I didn’t copy over everything), dump a copy of my installed packages (which i ended up not using ;p) reinstalled, and copied over what was needed – in my case web server configs and pretty much nothing else.
Suprisingly painless!