Yes, actualy you kinda have to, all plants are somewhat winter hardy, but will die off after the fall and roots will rot away. So even if the winter is soft, you got to do a major cleanup after each summer. And in all those years i only had 1 winter soft enough to keep the fish outside. But when it starts to freeze to much i realy have to get them in. So im always prepared for that. I always start a tank up inside on time for the fish, so they have a warm welcome inside the house for the winter if needed. If you do this in a region where there is cold winter, you need to prepare to take care..
Imagine - 12 celcius, what do you think happens to the tub?