Bill IIRC at 55 LMB metabolism is just starting to slow but the winter prep eating binge is in full swing so they can add lots of fat for winter. That is why with winter temps at 50-55 the LMB in SoCal and central/south Fla are so big and fat - the gorging process continues unabated most of the winter. I would think that HSB do the same but keep the eating process going to a lower temp. I will find a thread where the winter prep process in discussed.

Here is the thread :

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=7;t=000315;p=1

Here is the ref. :

Transactions of the American Fisheries Society 111:549-558, 1982

Energy Partitioning in Largemouth Bass under Conditions of
Seasonally Fluctuating Prey Availability

S. MARSHALL ADAMS , R. B. McLEAN, AND J. A. PARROTTA