Use PowerCLI Set-HardDisk and Invoke-VMScript to increase the size of many virtual machine hard drives

Today I decided that I wanted to increase the C: volume of 20 VMware Horizon View parent virtual machines (the source for 1,000s of linked-clone virtual desktops) from 40 GB to 60 GB. The normal/painful way to do this would be: vSphere > select the virtual machine > Edit Settings > change Hard Disk 1 …