Enabling WIDE screen on KVM / virt-manager console


Host is Linux Mint / Ubuntu.
When you click full screen in virt-manager, the VNC or Spice console is bigger.
But the console does not occupy the entire physical display area,

Even without full screen, I want to widen the console to cover the ENTIRE left and right sides of physical display area.

NOTE: Maximizing the console window using its top right icon does not widen the console window.

How to you do enable WIDE screen console in KVM?