re: "My style would be to talk to them..."
Oh, brother. As you noted, it's only for a month. GET OFF YOUR HIGH HORSE! Who appointed you the arbiter of good taste, anyway? Do you react the same way when people in your area overdue it with the gardening or fertilizer use? How about the colors they paint their homes? How they dress? The behavior of their children? If not, WHY not??
I commend you on one thing in your post, though, if you would REALLY discuss the matter with your neighbors instead of threatening them or otherwise preventing them from doing what any free person should be able to do. That's most uncharacterstic of a liberal - who will usually dodge personal involvement and instead expect the police or the city hall to do trivial dirty work for them. Want it your way? Call friends and political connections and pass a new law or regulation. Take away or tax someone else's freedom. So, if you would REALLY just talk to them, you're doing the right thing even if your issue IS misguided.
Out of curiosity, what would you say to them? "Howdy neighbor. That sure is a gaudy, tacky display that you spent a dozen hours putting up this weekend. How about doing me a favor since it hurts my eyes when I'm indoors and turn it off at 9 PM?"
Hah. No wonder so many people hate each other these days. Someone tries to do something nice for the community and ONE overly sensitive person gets offended and ruins it.
About that 9 PM. Is turning off Christmas lights at 9PM mandated in your area? Is it the norm? It sure isn't in mine. I stepped outside to see and I don't think ANYONE'S lights are out. It was 9:45 PM where I live (same time zone as you.)
About the light display. It looks well within the range of normalcy. Some, myself included, think it is GREAT that people do that, btw. In Sacramento, the neighborhoods that really go all-out with their light displays make the news - as places people should visit if they'd like to really get into the spirit of things. Neighbors compete. I have photos of my mother-in-law's neighborhood where ENTIRE LAWNS have been netted and lit. I have no idea why this bothers people like you - except that MAYBE as a country bumpkin, you're badly out of touch with what goes on in suburban neighborhoods these days.
Take a look at the three photos below. The first is of the offending house. The second and third are pictures I just took a few minutes ago from my own driveway. They're my immediate neighbors. Are these light displays so different? And believe me, a LOT of people have more ostentatious displays than my two neighbors.
It's 10 PM now. My two neighbors haven't turned off their lights. I don't think anyone in the area has. I guess everyone here is lucky not to have someone like you in the neighborhood. You'd be pounding on their doors telling them how to celebrate their religious holiday.
The "offending" display.

My first neighbor.

My second neighbor.
