Shouldn't it be possible to use PowerShell Remoting?Not nearly as easily. You can't access the Update over PS remoting. The CreateUpdateDownloader() and CreateUpdateInstaller() methods can't be called from a remote computer. You get E_ACCESSDENIED.
Some other Powershell modules handle this by using Powershell create a scheduled task on the remote system. A scheduled task isn't great though, because it makes it difficult to get notified when it completed, and the results of the tasks.