The setting will most likely affect the plot in the way that the power failure will hinder the movie and video games as the girl, her parents and guests are not done yet with the cake and food at the table and as read in the story, they would afterwards watch a new-release movie, and later they girls would play video games until time to go sleep, but now with the power cut they will not be able to do such things because there will not be power for the TV not for the console.
You can also write: Writing stories in an outlet is what helps Francie avoid telling lies. As stated in lines 143-145, "What was important was that the attempt to write stories kept her straight on the dividing line between truth and fiction." This is all thanks to her teacher's advice.