No, I wouldn't cut back now. Very normal for them to drop leaves when they come in. Weather temps (air & soil) are all so different. Keep leaves picked up and plants damp to the touch. New leaves will form, come November I fertilize through April. Usually in May cut off my longest stems and make two or more plants our of one limb--I use a little (rootone) and make a finger hole and that is it. Geraniums are messy during the winter, I keep mine on the sun porch, but they do give the pleasure of flowers. Sometimes I take the vac pole to them. Good luck.