If there's *SOME* snow, you can ski!
I've been skiing daily for the past 2 weeks on about a half inch of patchy snow and icy leaves on the one-mile trail that goes thru our yard. But, ya know, it's still GLIDING! It works. And that's enough! XC is like walking with glide. Whatever gives glide will do. Of course, don't use fancy skis. This colder weather and bits of snow make for nice fresh air, too. Gotta ski!
[RELEVANCE UPDATE, 12/15: We just got an 8-inch dump. No more leaf-grass skiing!]