Q.Wintering hibiscus
When should you prune a hibiscus?
Waiting till spring is the better option for most types of hibiscus, as explained in this article:
Whether your hibiscus needs pruning at all, and how to care for them during the winter, depends on what kind of hibiscus you have. Some, like the Hardy Hibiscus, will die back to the ground in cold climates, but the roots will survive and sprout again next spring. Others, like Rose of Sharon, will keep their branches during the winter. Warmer climate varieties will need winter protection, such as mulching over the roots or wrapping.