Similar experience to 75 in #59.
We have a walk in chiller and unfortunately never thought about an extended rail when we set it up. The electric winch is on a gantry which swings through 90 degrees from door to cold store. It can also slide along about 1 metre of the gantry rail. When loading reds single handed we put a webbing strap around the red just forward of the point of balance, winch it up keeping a hand on the legs to keep it level. Swing gantry and offer the deer up to the door. When you take your hand off the legs gravity raises them to the height of the rail and you can proceed to hang your deer
Incidentally we used spurious door hangers and rail made by a local engineering works. The threaded bar was heated into an S. It means minimal loss of roof space