How well do the rope drop plans work during the holiday season, Christmas?

The plans actually work best when the park is the most crowded because the wait time get so much higher during the middle of the day. What I would suggest is arriving even earlier, however, than you would during another time of year. When crowds are at their highest Disney will often let people onto the rides a little early to help spread out the guests as much as possible, so I would recommend arriving around one hour before the park is scheduled to open so you can be in a good spot in case that happens. The more rides you can get on in the first 2 hours, the more you can relax when the park gets really busy.