Something I keep seeing is "traditionally" Yule would fall on the next Fullmoon. There is no set traditional specific date for the Yule celebration nor the amount of days. We have a variety of sources on these matters though none specifies the specific date for any celebration. At best we have "at Midwinter." Well when was that? It arguably varies from tribe to tribe as the calenders of each that we have shows a root from which each slightly varied. None of them specifies a date for it either. The best I've seen is the calender according to Bede which shows a clear distinction between Ærra Ġēola, the month "before Yule" falling roughly around December (not exactly however) and Æfterra Ġēola, the month "after Yule" falling roughly around January (not exactly. Some suggestions would put the dating of Yule in between the two months somewhere around the end of December most likely or even early January.

In all of this we could go on and on about these theories, but in the end WHEN WAS MIDWINTER? That would be the only way to define the date.

I see no problem with celebration on the Solstice nor on one of the surrounding Fullmoons. Either has valid arguments. Tap into your roots and find what fits and progress as you learn more. That is all anyone is doing now and can be expected to do. No magic guru has all the answers, but some perhaps.