They are hardy in the ground here, where our lowest temperature is listed as zero degrees. It's less risky to let them stand until spring without cutting them back, especially if your winters are wet. Hanging baskets might not make at as low as zero degrees.

They can take some frosts, however, the top will start to die when it gets below freezing. How are your night temps? I'm in 6B zone and it's going down into the 30's here, then a brief warmup in the 40's at night. When I see the leaves with a purple hue, then I use that as my last safe point to save the plants. My lantana hangs on until around Thanksgiving/early Dec., then I let it die out. Now whether the roots are still viable at that point, I can't be certain. If you want to save the plant, I wouldn't wait too much further. The poor plant will have reverse shock, from freezing cold to warm inside temps...LOL. With warmer temps these days, you may get a little more time outside with the plants, though.

The nights have been in the low 30's and even some high 20's. I've noticed some purpling on the top of the plant, but everything else looks good. The next two nights are expected to get into the high 20's again with a slight warm up, so I'll put them in the garage until the "warm up", so I can keep them outdoors as long as possible. After that, it's in the basement where it will get a trim, tiny bit of light and little water (the temps will be over 32 degrees). I figure this will simulate dormant conditions and hope for the best for the spring!!