I live in zone 5, Canada, and have several hardy hibiscus. Here we get killing frost in October, and sometimes September. The hardy hibiscus goes quite brown, and begins to die back for the winter. I let it do that for a few weeks, and then cut it off at about 6 inches above ground. It comes back in the spring when the temperature is warmer, although it is one of the latest ones to come back. I have 5 different varieties, and they all do the same. They have been planted in the ground though, so have developed good root systems to help them survive. Yours being in a pot may be different.

If I were you, I would be tempted to "take a chance" and plant it immediately, and allow it time to further develop its roots. I would also be tempted to mulch it this year, although it is not normally necessary.

I have many different types of tropicals though, and they have all been brought indoors and will spend the winter under lights. I honestly don't know how the hardy hibiscus would take this treatment though.

"Hardy" usually means leave it in the garden ... in the ground.

you might have waited too long to have planted it with the weather turning colder here now,I also live in Va and grow several varities of hardy hibiscus..U could cut it back as jroot says and winter it over by digging a hole and planting the whole pot into the ground preferbly near your foundation then placing some type of mulch over it like leaves is what I usually use then come spring pull it up and plant or winter it over in a garage where it wont freeze just make sure it doesnt dry out if u do that but you still want to cut it back as jroot posted it will come up late in the spring and grow very quickly on new stalks..hope this helps u....Tomva