If you are traveling to a family tourist destination at a time of high demand -- such as when your travel dates correspond to school breaks in your metropolitan area and many families want to travel -- it's usually best to book far in advance. Prices are likely to go way up as the travel dates get closer.
If you are traveling to a family tourist destination when demand is low -- such as when school is in session and there are no major conventions at your destination -- there can be good sales a couple of months before the flight dates as airlines try to sell seats that might otherwise go empty.
Dec. 21 through Dec. 31 is period with significant demand for winter vacations and families getting together for the holidays. This is offset somewhat by reduced demand by business travelers because companies tend not to have meetings during the holiday period.
Los Angeles is a tourist destination and a connecting gateway to the Hawaiian islands and Asia. It's also a major business destination.
If I were traveling to Orlando from Dec. 21 through Dec. 31, I wouldn't wait any longer, especially if I wanted to avoid early morning and late evening flights. I would bite the bullet and pay the current prices before the prices go even higher.
If I were in your shoes and traveling from Columbus to Los Angeles from Dec. 21 through Dec. 31, I might watch flights for a few more weeks before buying. There might be an airfare sale (although the airlines may exclude flights that are likely to sell out anyway). Recognize, however, that waiting is risky because the prices could go higher.
Is it essential for you to fly into LAX instead of one of the other Los Angeles area airports (SNA, LGB, ONT, BUR)? I would also check fares and schedules into the other airports. The prices can be higher or lower than LAX. If you're going to
Disneyland, SNA and LBG are much more convenient than LAX.