Description of problem:

Is it possible to add a warning message to the XL container size selection so that data scientists can see that they may not be able to start an XL container size because there aren't enough resources on the cluster? During a usability test, several data scientists just selected the XL size container because they thought they were working with large data and wanted as many resources as possible. However, the server did not start then because of insufficient resources. 

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Launch JupyterHub notebook server
2. Select X Large from container size

Actual results:

Expected results:

Reproducibility (Always/Intermittent/Only Once):

Build Details:

Additional info: