Reply back professionally with appreciation

Thanks for checking in with me. Yes, I received your email, but since we don't have an opening date yet, we haven't made plans in regards to food truck vendors. Once we have a more definitive opening day, I would be happy to discuss having you guys and your food truck at the distillery.

Thank you for reaching out and keeping us in mind for your future opening. We completely understand the importance of having a confirmed date before making any plans. We appreciate your consideration and look forward to potentially working with you once the opening day is set. Thank you again for your interest in our food truck.