You can leave them out for the majority of winter. Bring them in if a freeze threatens then take them back out in the morning. If it's a light freeze you can probably just wrap them, move them against the house or the garage & wrap them up, water them really well too.

Don't fertilize after this month. Water less than usual but don't let them get dried out, you'll lose some leaves just from moving back & forth, don't worry about that. And whatever you do don't cut them back until the end of February, first of March. You know we have those warm days & the plants send out new growth, pruning encourages the same & the new growth, of course, is more likely to freeze.
Tally HO!

The last two winters I've brought a tropical hibiscus into the house and kept it in front of a large window. I watered from time to time. It was still healthy by spring when I put it back outside. I intend to do it again this year.

As I understand, tropical hibiscus have shiney leaves and must be protected during cold weather. Hearty hibiscus have dull finish leaves and can stay outside.