I expect that there is a lot of space in all the royal residences so social distancing would not be a problem.
However we will almost certainly spend Xmas by our two-selves, for the first time in fifty years, in spite of having a spacious home.
We all have to make our own assessments of risk.
We are only in our seventies and we hope to live longer, long enough to get out to the other side of the pandemic and be with our family, close to them and able to hug them all at some time in the future.
If we were in our nineties, we might decide that it is better to hug them now, in spite of the risk.
It is a case of balancing quantity and quality of life.