In a previous post our CE's job was at least one day a week (of four) doing presentations. Her approach was to have one of our comms team charged specifically with assisting her with the presentations. They had maybe half a dozen different off the shelf ideas that they had come up with at some point, and then each time she had a presentation to do she would scribble some changes on a print out of an old presentation that was similar to the one she had in mind. Then the comms person would do their thing, and they would get together and review it ahead of the presentation.
This worked really well for them, for several reasons. After doing it for the better part of a year, they had a really good understanding of how each other worked; they had a really good library of material, knowing what worked and what didn't; they built it into their weekly routine so there was never a feeling of last minute-ness; they both learned from each other.
Now obviously its easier if you work in a medium sized business that has its own comms department, not all do (tho more still probably should). But you may find someone in the company that would like to take this on as an opportunity to work closer to the CEO, which is normally something of a boon. You might want an external consultant to provide a bunch of high quality starting material, but you will still need to tailor it every week, often with small but time consuming changes that are not the best use of a CEO's time.