Starting catnip indoors from seed or cutting (in autumn)

Anyone grown catnip from seed or a cutting as an inside plant in the fall? Cocheezie is having such a great time in the little patch and she will lose it very soon to winter. I don't know if I can harvest the seeds. She ravaged the last remaining plant with seeds quite badly. It may have to be a stem cutting - should I put the cuttings in water or directly in plant soil? The only rooting medium I could find was for trees. Any help appreciated. My thumb has no green in it whatsoever.

I haven't tried growing it indoors, but it's a mint so it should be fairly easy to get going, I'd think.  I usually put cuttings in water until they get some roots going and then transplant to soil.  

Perhaps others with more experience with indoor gardening will chime in.  

I've put 3 cuttings in water (with a rooting stimulant added), and repotted 3 plants (that may be a different kind of mint). Hoping for the best. Soon, it will be too cold for her to go out. She doesn't have much insulation. I'd rather food first go towards fattening her up rather than keeping her warm. Though convincing her that it is not wise to go out will be a challenge. Cat logic is unarguable.