Time to get rid of these plants?
 

or can we just cut the dead parts off?

thank you.

I would cut off the dead spots and see if it comes back.

I'd cut off the damage and wait there still what looks some green healthy leaves.
The first plant pictured looks much better than the second

Looks like Ann Marie Lantana's (CORRECTION! PENTAS) ??? We have about 9 of them in our brand new landscaped area. All but one has turned to dust. ONE has 1 stem with 4 green leaves remaining but the rest of ours are definitely deceased. Yours seem to have some life left. In our case there is no chance they will come back as when you touch the stems the pulverize. Pretty flowering plants but the company who did it should know they aren't "cold friendly" or at least given us a warning and another option. My wife asked for "color" and that they are, I mean were! "They" say wait until late March and see if any come back. Ours won't.

I agree.

Yes, 86 them. They are pentas not lantana. Inexpensive to replace. Last frost date for zone 9a is March 10th.

Yep, upon blowing up the photo I see my error. I switched the names as we have both. 4 Pentas and 9 Lantana's and our Pentas are also dead as our Lantana's. Guess around here they become annuals and not perennials. :(

Can you suggest a "pretty" flowering plant that can survive one or 2 nights of freeze? These obviously could not.

This is the remnants of ours. Barely identifiable. RIP :pray:

Dianthus and salvia and pansies are a safe bet for now. Good luck!🍀

Wait until March. Some of those plants appear to have some green at the base. They may come back after cutting off dead parts in March. Many of the plants we grow here in The Villages are not dependably hardy such as tropical hibiscus, cardboard palms, Thai plants, crotons, etc.. I was on a bike ride recently, out in the country near here, and saw a number of good sized Bismarck palms turned all brown. They are rated for zone 10. We are 9A which is even colder than 9B (Orlando) so if a real cold winter shows up many plants that are marginally hardy here will die. We have been lucky these past few years.

That is what we are doing with ours.

It may look unsightly, but having any new growth come up through the dead bits gives it support and some protection from the cold.

March is quite soon enough to take away the brown, if you even need to by then - it could be totally covered by lovely green!

I have had both of these and found that cutting everything off a couple of inches off the ground, often results in regrowth of the plant. Especially the weed Lantana.

They are Pentas a perineal that can be cut back and usually will regrow. A lot of people treat them as annuals.

Covering your plants before a frost may save them
 

I covered my plants each evening that I heard the temps would be below 35 degrees. Almost all survived. The poinsettias didn't make it even after being covered.

Plants
 

The second one is gone. Time to stop all treatment. Sorry

Be careful. If you prune/cutback too soon it will promote new growth which is even more susceptible to a freeze and will kill the plant.