Hibiscus growth will slow down as temps cool so it may be better to do it sooner than later so some growth and roots can fill the new pot and soil before you bring it in for the winter. Other wise if you can wait then consider next spring after it warms regularly above 50 so you have somewhat more active growth to fill the container. You can do it in the winter but watch watering as this is the slow growth time and overwatering can be an issue. I hope this is of some help and happy growing David

Like David, I have transplanted several hibiscus successfully, and (grown them in 24-inch diameter containers); both Fall and Spring seem to work -- after the plant is cut back. Good luck.

My mother bought me two hibiscus plants early this year (2010). I planted them in a spot that I "thought" I wanted them to be. As the summer went on, I decided that they really weren't where I wanted them. Now I need to transplant.

I did not realize that I needed to cut the plant back. The frost has gotten the plant tops. Is all lost now?
If not, I should wait until spring to transplant them?

I was moving a potted tropical hibiscus 10 years ago to my new house and it blew out of the pickup. The pot 24" smashed and a truck behind ran over it and dragged it 100 feet down the road. I had the tree for over 30 years so I put it in a pot and cut it back to 10" from 7'. within 3 years I was pruning for size control. maybe it was root bound and jumped out of the truck it did get a good root pruning that day.

I have found the common wild grown plant to be very hardy. So much so that I have pulled many out of the ground with my hands and transplanted without issue. I recommend more traditional methods but I think you get the point.