Yooperfan,
Yes, it will cost more for a King bed. It is the same rate as if you request a water or pool view room.
We haven't stayed at POR; but at the CBR the king bed rooms are on the corners. We would love to try it there sometime, too.
Keep in mind that even if you request a mansion room there is no guarantee that you will get it. You could get a room in the AB instead.
Don't know the time table for the remodel; but it should be after the POFQ is done. That way one is open while the other is closed.
Family lives in Marquette, too.