I’ve used the same process on a number of Digital Ocean servers, so it is good to hear this works as expected.
One point, it looks like you are on an older Digital Ocean server, so it has not upgraded the Kernel. You can switch (in the Digital Ocean control panel) the Kernel to the Grug 0.2 kernel, and then Ubuntu will use the latest version (4.4 something).
BTW, the Snapshot is definitely essential - I just tried this process and it corrupted the harddisk and refused to boot properly - I’m lucky like that. I restored from the snapshot and everything was good again (tried again and the same thing happened so now I’ll see what the DO folks have to suggest).
So kids, always do the Snapshot (ideally from a powered off state, event if that means your server is down for an hour).