In my community, we have a similar event each year; for our area, it is a huge event. Our little town has only one stop light, and our event will draw several thousand people for a parade of less than ten blocks. It is at night with few street lights.

I try to set up on the intersection or another location where I will have as much ambient as possible and minimal subject movement and average out my exposure settings. It does not work all that well. The float Christmas lights and the headlights from other floats blow everything out, and you can’t see much. Lower the ISO, and you can’t see the people, but the float lights look good. Flash is handy when it is effective, but often, it creates a mess of its own. Bracketing could work if everything was moving. Not every shot is bad bad, but most are with only a few mediocre ones. Rarely a really good one. I know what I am doing and I have good gear; it is just brutal lighting, any way you look at it.

As others have stated, go to the location prior at the same time of the evening and practice. It is street photography in the extreme.