Login Screen with Storyboarding possible?

I am playing around with the new iOS 5 features and trying to rewriting one of my apps as pure iOS 5 app using the new storyboarding feature.

To cut a long story short, I have a start screen where the app tries to connect to a server if the user saved some login data, if not, it should ask for them.

Here is how I would do it. I create a Viewcontroller which is doing the connection thing in the viewDidLoad method. If there is no login data or the login is not successful, I need a to do a manual segue to the login screen.

Now is this even possible, or do I need 2 story boards for that ?