Since we don't use it at $work much, except for personal projects, it doesn't matter. But if we did, I would just keep upgrading my VM periodically, and then checking that the production version still works for the code. As it is, it's probably time to upgrade again. Maybe after I update to Ubuntu 18 LTS.

Since everything seems to be going to the cloud these days, and the cloud providers tend to provide fairly recent versions, it makes sense to just keep ratcheting up, fixing issues as they come up in the version transitions. Because at some point, some feature will be deprecated, or some "it works this way" sugary tidbit that was never really intended will go away.