I have 10 hollies, 3 of them appear to not be doing well, possibly from the last two cold winters we had with extended below zero temperatures for a long time. The other 7 look healthy. I was going to replace all of them but am having second thoughts. Over the weekend I cut them all back to basically a stump sticking out of the ground with some short branches left on them. I have two questions, will they grow back after cutting back? If so, how long will it take to see new growth? Thank you!
Holly pruning varies with the variety of Holly you are growing.
You will need to wait and see. Some plants will do fine with a severe pruning, others may not.
Here is a link with more information.