If overwintering some of your plants, now is when you really need to pay attention to the weather because some of the plants need to be dug before a hard frost. It’s hard to do because usually, they are looking really nice.
Geraniums can be saved by shaking the dirt from the roots and putting them in paper bags and storing them in a cool dark area. Next spring, pot them, cut them back by half, fertilize and they be beautiful again next summer. Another method is to store them with soil around the roots. Cut the plants back by about half and keep them in a cool, dry place stored in insulation like peat moss or in their containers.