If you want it as wall art and never as a bed quilt, then you can hang it as art not as a quilt. Make a canvas - plenty of instructions on youtube for this, staple your top to the canvas. The staples should hide in the seams pretty easily.
You will be hanging the top as fiber art and while it will be a large canvas it is not an unusually large canvas for artists.Fold the top around the edge of the canvas and no frame will be needed. A canvas of that size will have at least one cross piece brace in the back and you can hang it from that with no problem. This is thinking outside the box for a quilter but quite common for an artist.