By that point, you don't need an AI that boils the oceans and hopefully doesn't confabulate or misinterpret your words, all you need is a better corporate travel portal, which is a legitimate workplace productivity discussion to have, and a solved problem with traditional methods. Ours is effectively close to the workflow you describe: picking dates and time brackets, destination, fine tuning flights and hotel options, sending for validation, less than 10 clicks through information-dense and effective/predictable screens which I wouldn't want to trade for a chatbot and it's usually over the top words salad.

A good agent would call you to ask clarifying questions and then actually get you that perfect seat, etc. ideally