Yes George it is possible and as Theo notes under your conditions is likely that some of them could do so. It is not uncommon for a certain % of CNBG in a good environ to go from 0 ( April yoy spawn) to 8 inches in your conditions by Nov. That is more than 1 inch a mth. That growth rate will slow or stop over winter. The second year growth rate in length will be less in age 1 fish ( 2nd year of life) but they put on some weight and girth.