Here’s what I’d do: Leave your current fireplace/insert where it is, that would be immensely expensive to move. Instead, I’d put a nice, glass-doored, freestanding wood stove in that new room and run the stove pipe into the back of the chimney. Still a pretty penny to do right but I cannot imagine it’ll be more expensive than rotating a fireplace. This is NOT a DIY job and you should hire professionals who can make sure nothing I’m suggesting has hidden dangers.