I second this (and third it and fourth it!)
The dashboard view should make better use of the available space, and even better yet, allow the user to size the thumbnail images. Then fit as many across as you can, then do as many rows of that many tiles to show all the cameras. Allows the user to have it view as many cameras at once as they like.
Also, for AC powered cameras, offer the ability to see the live view in the dashboard, simultaneously for all AC powered cameras. I understand that you wouldn’t want to do this with battery powered cameras - you could have those refresh based on the snapshot settings as mentioned above.