They are fine, in fact most people cut them after a freeze. Just cut them off, leaving a few inches of stem and then bring them in where it is dry. I would not put them in an unheated area, because I think they will just freeze and not dry out that way. You can tie them up and hang them from a ceiling if you don't have floor space for them. Check them often to make sure none are rotting. If so, throw them out. Be careful when harvesting not to damage the gourd because any cut in the flesh may cause rotting. They are 'done' when you can shake it and hear the seeds rattle inside.
I'm sure you can google it and find out more info. Some areas have a Gourd society/club and you might contact someone in your area. They know all about gourds- growing, drying,and artwork-carving them, ect. The local club here has a show every year open to the public and they have elaborately decorated gourds on display.
