If the porch has a door you could risk leaving them, but I would cut them back anyway - they will grow up again next year quite quickly.They need to be kept pretty dry in cold weather to avoid rot so even if you leave the tall stems on you might want to cut them back in the spring as they don't look pretty when half bare. You will need to keep them frost free.

Thank you Steragram. Very helpful. from what you say it's the same as the smaller pelagoniums. I wasn't sure with these being listed as taller, climbing ones if you left them. What you say makes good sense.

Erm, I'm sorry to disagree with my very good friend Steragram, but if you're leaving them in the porch to grow as sort of houseplants, don't cut back. You may find they start to die back a bit if cold gets to them, but at least the topgrowth currently present will give them a bit of protection during the colder months. If needs be, cut them back and repot in Spring.