I regularly work out/weight train for 120 mins continuously, but when I do I am not working the whole body. I usually work legs thoroughly, rest 5 mins with thorough stretching and then work 2 upper body muscle groups. I am thorough and it takes me this long. I do not think it is excessive: I am rarely completely exhausted at the end, just tired in a good, "I worked out hard today" way, I am getting good results and I enjoy it. I do take the odd total week off to thoroughly rest the muscles and also prevent mental fatigue and boredom from seeping in.
APE might be too much all in one go if Amy is working every muscle to exhaustion all at once. You want to feel fatigued, like you deserve a great meal and hot shower, not like someone has wiped the floor with you and you need medical assistance to get to bed!
I think longer workouts are something to work up to, they are not for beginners. But also, I think it depends upon your mind set and what works for you.
You should certainly feel free to carve up APE into sections and spread it out over 2 or 3 days. Amy herself would be the first to encourage you to do exactly that!
Clare