At this point wait-and-see is the way to go, but I think in colder climates like OH, standard roses (the ones on a long stem with the branches all at the top, like a lollipop) need winter protection, like storage in a cold basement. There was a vendor selling cold-hardy standards--'Polar Joy' was the name. Here's a thread about it: Here is a link that might be useful: thread about Polar Joy hardy tree rose

Im sorry but unless they are a hardy species, they are gonners for sure. The only hardy species I have ever seen with a braided trunk was a rose of sharon, they usually have pink blooms, but occasionally are white. If the blooms on your hibiscus were something like yellow, peach, orange, anything that looks tropical, it probably was. I have seen hibiscus die in florida. They lose most of there leaves after a light frost and the coldest temp mine has ever survived was 28F (and I really have no idea how it survived). Still it lost all its leaves and didnt flower until october (and since it was cooler outside the flowers werent as nice). Basically your plant is probably dead, but keep it until mid may and if you get any growth at all, it wasnt tropical and will come back. If nothing happens, its dead.

Cut back the dead stuff for neatness sake but it has no effect on the plant. It's bone hardy and should start sprouting if it's survived the harsh winter you had over there. I don't know when it should start in your zone. Here it's already 8 inches high.

Tell us more. How did you cover it? Did you do anything else to protect it (add mulch, etc)? I have a couple of different banana species growing year-round outside. I don't do anything special for the Musa basjoo. It's completely hardy here. I did cover my new Musa velutina. I also encased it in pine straw for a little insulation. I'm hoping that once it becomes well established, I might not have to do anything to protect it during winter.