Depends on a lot of factors. We have a lot of our elk go down in less than 10 yards. Others have been surprisingly long.
Blade sharpness, blade material, blade hardness all play a role. As does each person's definition of "Well Placed". My big Oregon 7X7 never took a step. He flinched as the arrow went through, then about a second later his legs buckled and bounced a few times and down he went right were he stood when the arrow hit. A similar shot on a spike bull using a softer stainless two blade head resulted in a blood trail of over a quarter mile before I put another arrow in him with a lucky 120 yard shot. Who knows how much further he could have gone without that one

You put a three or four blade head through the aortic arch and no elk is going to make it 50 yards. Center both lungs with a sharp head and no elk is going to make it 100 yards. Miss the heart and only get one lung...could be a long day! That's why angle of shot is so important when hunting elk. Try to picture the path of the arrow
through the animal. If you can not get both lungs or hit the top of the heart - best to wait for a better shot! Toughest game animal in all of North America if you don't get double lung. Or you shoot soft blades.
I would say our "Average" recovery distance on elk taken with a "Well Placed" arrow had been less than 50 yards. Probably more like 30 when going through the aortic arch.