I tried growing mine in front of a sunny window indoors in the fall last year, but the leaf edges would get crispy from lack of humidity.I think they did better where it was cooler.There is another way to save them over until spring I think, but this is the method I went with keeping fingers crossed.

What I did with my two Geraniums plants in the late fall was, first, took them both out of the urn they were growing in and re-potted them both together into a shallow plastic pot with soil from the urn, then placed the pot in our heated garage (55 degrees)placed the pot in front of a north facing window without curtains for the winter.

Watered when the soil was dry, maybe every ten days to two weeks. Colder temps will keep the soil moist longer.
I did lose some leaves which had yellowed, but it was still ok. The plants looked like the kind Charlie Brown would have, but they both survived and flowered profusely this summer. I now have four plants instead of two and I didn't buy any new ones!

So I guess it's safe to say, find a cool place, indirect light and water when dry. Put it back out in the spring when warmer and there is no danger of frost. Move to brighter and brighter outdoor light gradually.

Susan
AKA DowntoEarth