No. AES and Enviro-Septic® were thoroughly tested in Canada in order to confirm that extreme winter conditions does not have an adverse effect on the functioning of the system. In general septic systems are not prone to freezing. Bacterial activity generates heat, and the septic field is regularly dosed with warm water from the septic tank.
We have seen distribution boxes freeze because of improper venting or a lack of foam insulation, but even this is rare and is more problematic in northern New England and Canada.