On this short notice, you really need to look at what's happening this year as opposed to historical records.
Sunshine and Louise tend to accumulate snow gradually and are usually rocky in December. Their numbers look better than a lot of US resorts now, but are in fact about average. Eyewitness reports from a week or so ago said lots of rocks. Sunshine has had 22 inches in the past 4 days, so much of it will be good even if the steeps aren't ready yet. Reports from Louise are not good.
Fernie has snow up high, but has had a lot of rain and the lower mountain is marginal at best. Castle may be a little better from its higher elevation, but it will not open until Dec. 15.
Kicking Horse will be opening for the weekend of Dec. 8-9, then daily from Dec. 14. There is a 55 inch base at 7,000 feet on 86 inches of snowfall since Nov. 1. These are the best numbers in the region, but that's 2/3 of the way up the hill and KH's base area (to which you must return after ~3/4 of the upper runs) gets about 40% as much snow as the 7,000 foot plot.
