That hanging is spectacular!
If you want to tackle an outdoor version you could try a flag made out of ripstop nylon; just applique the same design on using a satin stitch on all edges, and border it just like your quilt--that's how the commercial flags are done--and it could be hung on a pole or flat on a wall. Or make a barn-quilt like sign: Since you copied the design onto fabric, you could use your same skills to stencil the design on a sheet of wood (or metal for better durability) using outdoor paint.