Do you mean geranium or pelargonium, because geranium are hardy and will just come back in the Spring.
This year I am trying a few methods I've been researching to winter propagate my dahlias, most of which I will leave in the ground, but hoping to get more this way.
I have a tree form non-hardy hibiscus that is on year 3, doing really well indoors over the winter, even blooming. I'm also going to try to create a tree form of my lantana, which will require bringing it indoors. I have an olive in a pot that will come in for the coldest weeks. For all of these I also will put them out on a heated porch on sunny not too cold days.
Usually for hardy perennials I save seeds and sow some in late fall and some in spring and let what happens happen.
Last year I managed to keep fall pansies going until spring.
I took cuttings from hydrangea, asters, and sedum and just put them directly in the ground, all of them seem to have rooted. I tried that with roses too, but it failed to root. I may try rose propagation in pots indoors this winter.