It's best to bring in your plants indoors before frost happens. Help your geraniums make it through the cold seasons by placing them in a sunny window if you wish to overwinter them and have flowers, they may not be perfect, however can flower in bright light. You can take cutting as well not in fall, the cutting can root and may outlive the mother plant.

Now in Fall:

If you don’t want to repot again, you can carefully loosen the soil a bit with chopsticks, as compaction near the geranium stems happens over time with waterings.

Cut the plants back by a third to a half. Save the cuttings and root them to make more geraniums!

Geraniums overwinter best in a sunny window with temperatures around 60° F. They do not do well in dark or overheated rooms.

Helpful Links on YouTube caring for your geraniums (here: https://www.youtube.com/watch?v=QL7Z56oy9B0   & https://www.youtube.com/watch?v=-FJXiPpULug

Hope this helps.