i'm going to go with a bit over 4 inches.

I'm saying that because anything more than that, particularly overnight, is a pain in the ass to shovel once the plows have their way and swamp the end of my driveway and sidewalk, and not 10 minutes ago my wife asked me if i was going to get the snow blower ready, and i said, "No, i don't think its worth it"

This also means that if we do get over 5 or 6 inches, the rest of march will hinge on if i decide, "Fine, i'll get the snow blower ready" (in which case no more snow) or substantial dumps at every threat if i don't get it ready.