Hibiscus: What do I do with my Hibiscus acetosella 'Red Shield', 1 by Windy

Windy wrote:
I sowed seeds of this last spring and got two plants. One plant grew well over six feet tall and another only about four feet. It didn't have time to flower before the cooler weather and light frost came. They are still alive and I want to have the chance to see it flower next year if possible.
Can I cut it down to a couple feet and pot it up and bring it into the house or garage? Can I take cuttings from the tips and root them for next year? It took me a lot of trouble to get them this far and I do want to see them flower.
This is the taller one back in the summer, it is taller and the stem is thicker now.