Here's the problem: You know MSM looks amazing, you want to go see and experience it. So does the rest of the world. A lot of them have the same plan as you: a quick stop at MSM, mid-day.
You can try to squeeze in, into the very limited space on the Mont, while hundreds of other people have stepped off tour buses and are trying to do the same thing. It's pretty easy to imagine what it's going to be like: the tiny, narrow street -- there's only one street -- it's narrow, lined with shops, does not go very far, and at midday, it's going to be absolutely full of people who had the same idea as you.
You can make your peace with that, and have a shared-with-mass tourism experience. Just calibrate your expectations of exactly how "shared" it's going to be.
Or, you could tweak your plans so as to only share it with a relatively small number of other visitors. Do that by staying overnight in one of the few (expensive, ultimately imperfect) little hotels on MSM itself. Arrive at MSM mid- to late-afternoon. Note the large number of tour buses idling in the parking lot. Note also the crush of people in that one little street. Make your way through that crowd to your little, expensive, imperfect but perfectly tolerable hotel on MSM itself. Wave your credit card and don't think about how much cheaper it would be at the local Motel 6 at home, you're paying for location location location. Note how all the crowds of people are moving towards the fleet of tour buses. Note them start to drive away, and how the crowds thin out at the end of the afternoon. Savor that. Enjoy the evening on MSM in relative peace and even solitude. It'll be quiet, magical, dream-like. Go to bed and sleep deeply. Wake up early (really early) the next morning. Go out and savor the quiet again, for a couple more hours when there are nearly no tourists at all. Eat breakfast, note that rumble you hear in the distance -- the day-tripper tour buses are coming. Check out of your hotel. Squeeze back out through that little street, now becoming jammed shoulder-to-shoulder again. Take a few last photos as you depart. Then go, and don't look back.