I have personally caught a good mess of brim on various trips in the winter. I rarely target brim in the winter, but on those trips I have done well.
I find them in deep water around cover. If I go it is usually for shellcracker and brim, and before the end of the day I have a right good mess of both or either of the two.
By the way I've never seen a "sluggish" brim...they always try to pull me out of the boat...even in the winter.
Happy Fish'n
This only my opinion, but nothing you can say will change my mind. That makes it a FACT.
Today is a Blessed Day and a Prosperous Day