I think that it would be useful for an Orion server to display an alternate site to Orion when it is offline.
This could be as simple as displaying a page saying the Orion system is down for maintenance with contact details for the administrator potentially.
The caveat that I see with this is that a second IIS site would need to exist on the Orion server and this would need to be brought up using the port mapped for Orion and I assume this would have to be done as part of stopping the Orion services.
Just a thought....
Ben