To generate longer text, it’s helpful to first make it generate a synopsis of the overall text.
Then, break the synopsis into parts, and prompt something like:
“Here is a synopsis of the script for a podcast: {synopsis}. Given this synopsis, we’re at part 8, ‘ask the question about stuff’”; write the detailed interaction and dialog between the host and the guest for this part."
Do this for each step in the synopsis, and the complete script is the concatenation of each of the outputs.
You might even be able to request each of the pieces in parallel, to make the overall job finish faster.