In Maryland, I advise people that not finding larvae at this time of year is
perfectly normal.  After all, what good would the new bees do?   Queens
generally take a break from laying eggs this time of year, and they start up
again in mid to late January.
 
However, there are always surprises.  I have found brood (and even drones) in
December.
 
W. G. Miller
Gaithersburg, MD