Can you define pre-Pagan? Pagan just means not Christian.

Are you asking what Christmas traditions are older than the contemporaneous religions during the development of Christianity? That's how I interpret what you are asking.

The dating of Christmas to Dec. 25 is unrelated to the dates of pagan holidays. In the second and third centuries when Christians were trying to add up when Christ was born, they drew off of the popular trope that really important individuals often died on the day of their conception. Considering Jesus is held to have died around the Jewish celebration of Passover, early Christians dated the death of Christ to March 25 (or sometimes April 6), and the Feast of the Annunciation is still celebrated on this date. Nine months after March 25? Bingo. In a sense the solstice is the basis for the dating in non-Christian and Christian winter holidays, but only so much that Passover is fixed in relation to the Spring Equinox, nine months before the Solstice.

So Christmas doesn't really come from these pre-Christian celebrations, though that doesn't mean traditional practices weren't incorporated into Christian celebrations. Admittedly, extra-Christian traditions during the Christmas season is not a subject I am all too familiar with, and hopefully someone will be along to help you with specifics, but it seems to me perfectly natural that the traditions associated with 'pagan' holidays would rub off on the celebration of Christmas. People don't drop a lifetime's worth of cultural practice when they adopt a new faith system. Throughout late Antiquity, we see a continuation of funerary rituals among Christian families that some might consider 'pagan', but in reality were just a part of a continuation of cultural practices among new adherents to Christianity. While I may be getting dangerously close to speculation, I think that traditions associated with pagan winter solstice holidays found in Christmas can be read in similar terms. People have traditions, and even when those traditions are no longer representative of a clear belief, their continuation or association with a new holiday is not so much an indication of holiday hijacking or closet paganism (though what exactly 'conversion' is can be a tricky term to nail down sometimes) as it is a testament to the extent to which certain practices and traditions can survive and coexist with new belief systems.