Your question is User Research With Limited Resources. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You need to conduct user research for a product redesign, but you have limited time, budget, and access to users. You still need enough insight to make sound design decisions and keep stakeholders confident in the direction.
What is your approach to conducting user research with limited resources?