Many succulent plants are a little sensitive to cold, but can also easily withstand frosts, provided they do not last too long and that the growing medium is dry. So in the winter we can place them in the garden or on the terrace, but protecting them from the humidity of the environment with plastic sheets. You can just put your succulents on shelves, covering them with plastic film, or if you live in an area with mild winters, you can plant them in the garden and build small tunnels around them, to be covered with plastic film. Even many bonsai can be placed outdoors during the winter: especially bonsai cultivated from native plants, also found in the wild. These plants can stand the cold, but the small pots of the bonsai do expose the root system to the cold. As regards bonsai from outside it is therefore important to place them in a sheltered and sunny position, so that the earth contained in the pots does not freeze completely, which would also cause the freezing of the root systems of your plants. If you do not have a sheltered place for your bonsai you can concentrate on the soil contained in the pots: the best method to protect this is to cover the pots with agro-fabric.
Start by cutting a strip of agro-fabric, then wrap if tightly around the pot until you have covered the whole pot and all the soil, all the way up the trunk of your bonsai.