The plants we call geraniums, technically pelargoniums, are too tender for our winter temperatures. Fortunately, it's easy to put them on "hold" until the spring. Give them a big haircut and put them in the garage.
My garage is unheated and they still survive year after year. Water them just a little every couple of weeks. Sometimes, when I open the curtains in the garage, they will start blooming in February.
Generally, the plants start leafing out again in March/April, ready to live outside again in May. You can repeat this process year after year. I have plants that are more than 10 years old.