I am often asked whether plants and fish can live in the pond throughout the winter.
The biggest influence on overwintering the pond is your freeze line and the depth of your pond.
Your county extension agent will know your freeze line. If you don't use your county extension office for information office for info, start doing so. They are a valuable resource.
Your pond must be deeper than your freeze line.
I do not know your freeze line, I live in New Orleans where we don't have a freeze line.