Disappearing Portals

[321]

Anyone know if it is possible to make a portal appear and disappear based on a relationship?

What I would like to do is have 2 portals one on top of the other, but only one active and visible at a time, based on a global field that has the 2 related choices. I know one workaround would be to have virtually identical layouts, one with each portal, and when the user toggles, they don't even know they have changed layouts, but I would rather not do that.

Any thoughts / ideas are greatly appreciated...