I love the Red Bird of Paradise shrubs. You just can't beat them for great summer color. These plants are actually native to the West Indies and tropical regions of Mexico. They can take the heat but look their best with moderate irrigation. The above-ground stems can be damaged by frosts but are usually root hardy and grow back each year when the weather warms a bit.

Pruning to the ground now may not be the best idea. The plants are still growing and blooming. Any green leaves are manufacturing sugars that the plant will begin storing in its roots for next year. If you remove them it can actually starve the plant. If your plants need some minor grooming at this time of year (like removing about 12 inches of spent flower stalks), you can do that safely now. That will encourage some interior branching that will create a more dense shrub.

It isn't necessary to prune these plant all the way to the ground in January unless the canes suffer frost damage. In warmer locations they tend to grow larger.

Here is a link that might be useful: Red Bird of Paradise