we went on a Monday, in order to avoid crowds. We had heard that some other Wall locations are over-run, and others are for intrepid hiker/climbers, so being good walkers who don't like mobs, we went to Mutianyu in mid-October and were pleased: very few people, fall colours just coming on. With the aid of a friend in Beijing, we hired a private driver to bring us back/forth from the city and were able to avoid an early start from Beijing. It was also a great means of learning about Beijing, as we picked his brain for all sorts of info. Total cost was $100 for two. We also thereby avoided having to go to a silk factory or other stop on a government-run tour, which is standard if you book through your hotel, it seemed from others' stories. The extra time was spent by me dealing with a bit of vertigo: I found one part of the wall to be much steeper than I expected and wasted about 45 minutes refusing to come back down! Suggest you consider bringing a walking stick to help reduce the pounding of the stone steps on your knees (I brought one as I was hiking several times on my trip). No need to climb up or down the wall: take the lift up and save your energy for walking along the wall. We road the sled down at the end: it was a gas, and much-appreciated laughs after my vertigo.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.