Ursula, there's always some attrition; it's the beginning of survival of the fittest. The problem with these tiny first season seedlings (n) is their internal seasonal time clock is not set until after the first winter chill and rest period. If I simply removed the green now and buried them, they would continue growing green* underground until the ground temperature gets down to near 32'F or 0'C. If ground moisture conditions are wet, that can lead to rot. That's why I wish it would hurry up and freeze, and freeze up good, so that any precipitation that falls will be snow that stays put and doesn't melt. It's funny just how seasonally adjusted and well disciplined these little babies will become by the time next fall rolls around (n + 1), they'll know exactly when to get ready for bed by then.
* Rick---how can this happen without the presence of light under 5 or 6 inches of soil, with mulch and snow topping. A couple of small leaves (up to) about an inch long are likely to develop and be just as green as if they were in natural light.
Speaking of Div. VI, now.