get-vm and get-vhd to derive per vm disk stats

(get-vm VMname | select-object vmid | get-vhd).Filesize works fine when I run it on the host where the VM is running

(get-vm VMname -ComputerName HypervHost | select-object vmid | get-vhd).Filesize fails when I run it against a remote system with the error:

get-vhd : Hyper-V was unable to find a virtual machine with the given criteria.

I'd appreciate any feedback.

Blake