You underestimate the powerful influence of Christian kids in a school system. Not just them, but the power of God, Himself, and of His Word.
Thousands of kids become believers every year because of the prayers of their Christian friends. They are invited to Church, to Sunday School, Bible class or after school outreach programs and I'm telling you that it WORKS. You don't have to be a wise old man like Paul was to reach others for Christ. Most people make up their minds early in life as to the path they will take. It is VERY important to reach people before they are consumed by the godless religions of materialism and socialism, and you can't reach them if you aren't there to become friends in the first place.
Thus, if you really care which direction this society is going, retreat is not the answer. If you, as a wise old sage, think you can reach the youth of America, please tell us how you plan to do it. I say, an army of thousands of kids who love Jesus can do the job just fine and they have been doing fine, with or without Silent Night, for many decades.
Do you gain any income from the government schools directly or indirectly? ( Just wondering)
Which they can do outside of school just as easily.