A customer that you were recently introduced to is considering

A customer that you were recently introduced to is considering beginning an RFP process to replace the solution they’ve had for 8 years and that we acquired 2 years ago. What questions would you ask to better understand the situation?  How could you turn this into an upsell opportunity?  Please provide at least five examples of exploratory topics you would want to gather more data around, and how you would use that gathered information to craft a business storyline around the value that can be gained from your solution.