I don't know. Since you're going to MK afterward, you'll need to park at the TTC, because you can only park for so many hours at the resort for a meal IIRC.
You're looking at a 15 min walk from your table to the turnstiles, unless you hoof it. IMO, it depends on the crowd at CM and its effect on how fast the characters get around, how long it takes to get your food in line, your picture taken at the beginning, your drinks/the bill from the wait staff, etc.
I don't think you'll be there for rope drop, but you'll be really close. So, like I said at the beginning...I don't know.