Staging plug-in?

Folks,

My site is currently on its live server, but I’m using the “Maintenance Mode” plug-in to keep it hidden while I tinker with it.

While that plugin is great for keeping folks off the site during major updates and tweaking, it’s not ideal for staging because it only allows me Dashboard access. It keeps me from seeing the site live, too.

Does any plugin exist that would hide the site from the outside but still allow the Admin to see everything? Short of having a staging directory or local server, would some hack besides a plugin work?

Thanks in advance!