I would say only once in the last 15 years can I remember snow levels being poor in Jan - but I had to mention it although the chances are very remote. Winter seems to be arriving earlier and earlier each year now so I would be very confident in saying you will have great snow by early Jan.
I will be there for Xmas so it had better snow before then!!!
I have ordered the snow and have it on good authority that it will be delivered on time. I am dealing with the same company that are building Wembley Stadium