Please include this information:

• What Grafana version are you using? 5.0
• What did you do? Edit a chart panel to change width.
• What was the expected result? There is no option to change the width.
• What happened instead? Nothing.

The only workaround I found was directly editing the JSON object. It seems strange that this has not been implemented yet, so I'm guess there is some bug in the UI that is degrading my experience.