I would plan for 1 - 1 hr 15 mins before Illuminations start.
I booked a 7pm reservation for 8pm Illuminations. We've done this several times and just remember that patio seating isn't guaranteed. Request it when you check-in and I always say we are willing to wait until one is available. We've been lucky and have always received a patio table.
Good luck!
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.