title: Upgrading a project to React 16 with old dependencies
body: <p>I would like to upgrade a project to React 16, because I have some dependencies that already rely on it. However, I'm also tailing a few very old React packages that I have not found the time yet to upgrade to newer releases that do support React 16. Now I need to buy some time.</p>
  
  <p>My project sources have kept up with the newer releases of React, but I wonder if there's anything that would not be possible to resolve for old dependencies that would cause them to remain completely broken with React 16?</p>