It is difficult to determine the exact cause of your cactus decline from the image. I recommend reaching out to the Oklahoma County OSU Extension Center for assistance. Samples submitted to the office may be needed. The extension office can submit the samples to the diagnostic lab if necessary.

https://extension.okstate.edu/county/oklahoma/

That is very possible. We have seen many plants, otherwise hardy to our winters, become damaged due to the extreme temperatures along with other factors such as mild temperatures before the sudden drop in temps as well as prolonged periods of colder temperatures. Hope this helps.

It is not recommended to just trim off the dead portions of the cactus pads. If it is severely damaged it is best to completely remove the damaged pad where it is connected to another pad. Here is a good fact sheet from the Univeristy of Nevada addressing pruning of cacti - https://extension.unr.edu/publication.aspx?PubID=2760.