Do I have to have all my content ready for the up-sell when I do my free webinar as a hook or do I wait to see first the response and then prepare a product tailored to the answers?

I'm a bit afraid of up to how much material / content I need to get ready before launching my first funnel with a free webinar. Meaning, if I launch the webinar, I already need to have the content ready for the online course I want to sell at the end of the webinar, right? Option A: If a lot of people sign up, then I have to have it ready so they can pay it and receive it almost immediately. Option B: If people don't sign up, then I invested a lot of time and resources creation a course that I can't sell.