That is exactly what I would do, is cut it back, mulch at the base least 6 to 8 inches. Then put a 5 or 7 gallon black plastic pot upside down over it, and place a small brick on top. It would still get air from the holes in the bottom of the pot, water when it rained. I do that with my exotic hibiscus. Then I take the hardwood cuttings, put them in a plastic pot with water, keep in a fairly warm place. In the spring I have new rooted cuttings. Albert taught me this. I never knew it was that easy, just using the light from a window. Barbra

Why do you need to take cuttings and grow them if your hibiscus was supposed to survive underground and supposed to sprout on it's own?
Also what is your hibiscus is rated as cold hardy at? I have giant hibiscus which seems to be cold hardy enough which do not require winterization but I assume you have tropical one?

My Esperanza returned from last year and it took all summer to get 3 ft tall and bloom. I'm in Arlington, looks like you are further North and it may not be as mild a winter. Soooo, I would dig it up and drag it in. If I have room, I'm going to do that with mine and I am zone 7b
If I can't I'll lay something on the roots that retains heat like that black rubber mulch stuff and mulch heavily with leaves. But then there is still lots of "hope" pun intended and no promise it will return. This was my first Esperanza to return.

Did you cut your esperanza down to root before winter?

I bring mine inside and watch all the leaves drop off!

All of my tropical plants are in pots and are pulled into a home-made greenhouse. I've wanted an esperanza but haven't wanted to add to my inventory of potted plants. I'd follow Honeybunny's instructions. The practice of taking cuttings to root is a fail-safe measure in case the winter is colder than expected and the parent plant doesn't make it. If it does, you can find someone to take any extra rooted cuttings at a plant swap.

I did cut it down and mulched it and put flat concrete tops for my concrete blocks on the roots to keep it warm. It put tomato cage with leaves over. Maybe that is what made it come through, but I think it was the lack of ice storms...only snow and a mild winter.

I cut back my exotic hibiscus, not my hardy hibiscus. Exotics will freeze if it gets below 32 degrees, and will not come back. They get about 3 ft tall, where as the hardy get 10 ft tall. Hardy hibiscus will freeze to the ground but come back in the spring. If trimming hibiscus, same as other hardwood plants, be sure not to cut back more than 1/3 of the plant or it will die. Exotic Hibiscus are very expensive, and hard to locate, I am trying to locate Dragon's Blood, have only found it at Charles Black Hibiscus. Does anyone know of another seller, that has it? I like plants that have at least 10 inch blooms. These are beautiful, special plants, that is why I cut them back, to protect my investment. Barbra

You managed to keep ground above 32F during winter time with mulch only?

Artisticcheese, my plants are in zone 9 coastal, just off the bay. Mulch will keep the ground from freezing. I learned this from a master gardener in San Antonio named Manuel Flores in 1994, when I asked for help on how to keep my bouganvilla from freezing in San Antonio, where it does freeze on a regular basis. My tropical, are in Rockport, it has only gone below 32 degrees twice in the past 19 years there. I lost all my tropical plants in 2010, so I do not want to take a chance of loosing them again, so I protect the most expensive ones. Torch lilies, exotic hibiscus, plumeria, hong kong orchids, and desert roses. I do not protect datura, brugmansia, gingers, iochroma, ti plants, variegated rubber trees, bird of paradise, bouganvilla, and a lot of other tropical plants and vines. In the spring I give the rooted cuttings to my neighbors, family, and friends. Barbra