I thought of a couple more ideas, one of which I used for a home haunt the previous year:
Holigeddon: Happy Nuke Year - In the final throws of the Cold War, after a decades long pissing contest between the USSR and America, the arms race becomes a reality as a nuke has hit the heartland of the USA, resulting in nuclear winter. The timing couldn't have been better as the Holiday Season is fast approaching, and the citizens celebrate the season with or without the risk of fallout. It's another comedy house as we have gritty doomsday preppers and mutants under the facade of Christmas cheer. Militants donning cheesy sweaters and gas masks along with improvised weaponry patrol the area to protect their own. We have elements like military barricades decked out with Christmas lights and garland, smoking missiles sticking out from the ground surrounded by smoldering asphalt, white stuff which could pass off as snow or fallout, etc.
I did this theme as a Trunk or Treat scarezone last year to a very welcome and positive reception.