The portal work in that way because we want to provide the ability to associate stories and bugs with the feedback and this make sense only in the context of a project. It seems that hierarchy of projects will solve your issue because you will be able to have a portal on the root level. We thought for such functionality before and now we investigate and re-prioritize it.
At the moment I can suggest you to put all your internal project in one big TeamPulse project and build hierarchy of iterations or areas to differentiate them. Something like:
the Telerik team