Best advice I ever recieved on fishing the Madison River - "if your boots are wet, you're in too deep". Got that from one of the guides at Blue Ribbon Flies in West Yellowstone. It's a big, fast river and there's so much water, but as others have said, if you break it down into manageable, bite-sized chunks, you can turn it into a series of connected 15-20 foot wide sections that are a lot easier to fish. Although I do get in the water often on the Madison, I've never felt the need to be a hero (or idiot) and try to wade to the middle of the stream when there's so much good water closer to the bank.

Regards,
Scott