Chance of a white Xmas Eve: 20%!.
Chance of a white Xmas day: 30%!.
Low risk of a few flurries to high ground in East Anglia on Christmas eve night / Christmas day morning.
Remember, a white Xmas is defined by 1 flake of snow falling anywhere in this region, so not everywhere will see the snow that defines a white Xmas if it occurs.