OP while I feel your pain. You were out of bounds. As long as there CG's there will be people up late around the camp fire. Some will be louder than others but it comes with the territory
If they violate quiet hours inform management. If management does not respond you may have a a civil (no attitude conversation with offending group).
If you still get no satisfaction complain to management in the morning and consider moving your site. Quiet hours does not mean go to bed in my book.
Ultimately management will decide what quiet is by there actions. You can agree or disagree. Turning on your high beams is just plain wrong and a foolish way to handle the situation. Luckily things did not escalate
I also would not expect total peace and quiet at a Lake George CG during peak season.If you are not prepared to encounter the public, boondock or choose CG that have larger more spread out sites where peace and quite is more of a sure thing.