If those Python services are going to last beyond 2020 and there's much risk of attackers probing for security vulnerabilities, I suggest you plan a transition to Python 3 during the remaining ~2-year support lifespan of Python 2.

It's a lot easier of a transition than it used to be. Any other support replacement language would of course also work to keep you secure, but honestly might be more transition work.

If you're a low-value target running unimportant stuff on an airgapped machine, this might not matter.