Ok now this is the tricky bit, there are two different ways to help your plant survive the winter.
1. Move the plant from its normal spot into a cooler but still bright spot, this can be outside however it must stay inside if you do get frosts as one or two of these will kill a VFT. The plant will die in a dark place as it will still need sunlight, you must still water the plant just less then normal, keep the soil always damp but not too wet, the plant will not need food.
2. Dig up the rhizome, spray it with anti-fungicide, put it in a plastic bag and put it in the fridge. You must spray it with fungicide or fungus will rot it, the plant does not need light or food as it is in a deeper colder dormancy however the inside of the bag must be kept slighty moist. This method must be got right or they will die.
I much prefer method number one, it is less complicated and is less risky but you can try whichever you want and good luck - you will need it!