Change model reference of a single viewport?


I have an existing- and a proposed- conditions model of my House.
In LayOut i have some stacked viewports set up, but now i realize i need one of them from the other model than it currently is…
I can see which model a viewport is from by selecting them while the Document Setup window is open.
But can i also change the source-file for it?
Creating a new viewport is a way, but then i have to also adjust all that i changed about it…