Andromeda is a whole other beast, but I understand we've done something similar for bodies in our Milky Way using two ends of Earth's trip around the sun.
Yeah, Andromeda is way too far away. The Gaia mission was custom-built to do exactly this kind of "stereo" imaging of stars in our own galaxy, but it's still not sensitive enough to cover the entire Milky Way.
Wouldn't any two points converge at the horizon, considering the distances involved, otherwise?