The Icefyre Conquest

At the end of Robert's Usurpation, Jon Snow had been born and brought to Winterfell while his paternal family laid in bloody ruins. Somehow, this time I and my twin sister went North with Eddard Stark instead of Jon Snow. What happens when due to some reason a boy with passable knowledge of ASOIAF is born as Daeron Targaryen, son to Lyanna and Rhaegar and brother to Visenya. SI-Jon