Agreed. Saturdays, any time after noon, are among the sweet spots for upgrades, especially for lower-tier elites, as few people want to travel then. Early Sunday morning is another one.

The fact that you were able to secure an N fare in the first place is a sign that elite load (and load in general) was likely to be light on that plane. (For anyone who's not aware: N is currently Basic Economy, but in 2016 it was still a deeply discounted coach fare, lower than G). I agree that there probably weren't 8 other silver elites at N or below, but it wouldn't surprise me at all if there were 8 non-revs.