Two or three times over the winter, fill a small tub with water, soak the geranium roots for 1–2 hours, then let them drain ...
Yes, you can overwinter them so they come back again next year.
When you find a geranium in the perfect color for your landscape, you don’t want to let it die with the first frost. And you don’t have to. Geraniums can be overwintered using three different methods ...