Hi
I think the best protection for most any tropical plant is to keep it dry , covering works wonders down to hard freeze .
I generally leave damaged leaves until frost danger has passed . Pruning causes stress and they don'r need more .
You don't mention where you live but winter has just begun in the northern hemisphere lol
I have had russelia survive with minimal damage down to 27 and recovered immediately. Of course potted plants are more susceptible to cold Good luck with it!!! gary

I live in Jacksonville Florida... actually right next to the beaches! So a bit warmer than Jax proper ! Thanks for the advice. I have it in a whiskey barrel outside

My landscaper cut my firecracker back to the stumps and now it has this gross orange slimey stuff on the top of the cut branches. It's still green if I scape a little of the bark away. Any ideas?