It depends what type of plant it is with the cold. The tropical Sativas can't handle it, but something like Kush can go and go. I have my plants in an outdoor greenhouse in Colorado. It's been in the teens outside, and in the 30s inside the greenhouse. The big tropical plants are still holding on, but won't make it much longer. The OG Kush and Strawberry cough plants are still putting weight on every day.
Having very large pots and being stingy with your watering will help. When plants are exposed to extreme cold they will minimize moisture in the leaves and stems in order to protect the plant. This means moisture gets diverted to the root zone. If your rootzone is too damp, moisture won't be able to move back and forth, and you risk a hard freeze. Water in the morning rather than evening so your plant isn't saturated when it gets cold.
You may look at the plant one day and it looks horrible! Leave the fan leaves and all the vegetation in place. It's all insulation, and it all helps manage temperature. Those leaves will die off naturally.
We grow a lot of weed in Colorado, and even in summer nighttime temperatures drop below 65, daily. Most folks out here don't harvest outdoor plants till the freeze gets close so they can take some cold. Good luck!