My geraniums on the outdoor wood fired oven hearth are liking November! They are hardy to about 30 degrees F but if the roots freeze, they are dead. I overwinter mine in their pots by putting them in my heated potting shed when the temperature is expected to go below freezing. In the spring, I clean them up and set them out again after adding soil and fertilizer. Geraniums are easy to start by taking cuttings of the green stalks. Cut off 4 inches of a healthy green stalk and remove all but the very smallest leaves. Insert each cutting in a clean draining-type  pot or container filled with damp potting soil and place on a sunny window sill. Keep the soil damp. If the stalk turns brown and shrinks in size,  it did not root, so remove the stalk and insert another freshly cut stalk. When the stalk grows new leaves, the new plant is rooted and on its way to being transplanted into a larger pot or for setting out in your garden when weather permits. Fertilize as soon as new leaves appear with a complete liquid fertilizer.