A white christmas is always nice to have, this would be my preference:
Christmas Eve: Snowshowers alternating with sunny intervals: -8°C / -2°C
Christmas Day: Sunny and clear: -12°C / -5°C
I prefer the longest day of the year also to be sunny/clear to enjoy the over 17 hours daylight and the short less than 7 hours of "night" that are not reached at all here in an astronomical sense between May and July.
Temperatures: Mid/high 20s during the day and mid teens (all Celsius) in the night.
As for my birthday (late March) i have experienced all kinds of weather from a snowy -2°C to a sunny spring day of 16°C, which is what i like. Well maybe a very late ice day (maximum below 0°C) or an early warm day with a high of over 20°C would be nice to too.