I don't understand the problem. The original date for Christmas was chosen to replace a pagan sun-god festival. There's nothing sacred about doing it a certain time of year. If we truly followed the early churches, we would keep on re-Christianizing the seasons.
In our church we used the first 3 weeks of November as a time of fasting and penitence. We started our feasting on Thanksgiving and will continue until Christmas. It honors the pattern of fasting before feasting yet allows us to give new meaning to the festivities. Many have already commented how different it's felt to participate in Christmas festivities this year. There is greater meaning, we enjoy the carols with everyone else, and the fasting created a space that allows us to enter in with true joy.
As a side-note, did you know that Caesar Augustus inaugurated a 12-day celebration called Advent to celebrate his birth? The early church just took that secular party and made it about Jesus.
An interesting tidbit is that the feast of the Annunciation on March 25th is actually quite a bit older than that of the Nativity.
The Nativity of Christ comes exactly 9 months later, on Dec 25th.
Thus, there is a strong case to be made that while Christmas did displace the "sol invictus" pagan feast, and coincides with the general time of the winter solstice, there may be ancient traditions within the Christian world that preserved the memory that the Archangel Gabriel visited the Virgin on or around March 25th.
Not a thing that is likely to be forgotten...