I think it depends on what you mean by "see"...as noted by the PPs, the prime viewing spots are filling up well before the parade's start time (at this point). My sense says that if you have a reservation around 6:00 pm, you can probably get back into the park by 7:30 pm (75 minutes to dine and then 15 minutes to get back into the park). It's hard to say whether parade crowds will be similar in August to how they have been now (when the parade is less than a month old), but my guess is that if you're going while it's still considered "summer", the crowds will be high, so the prime spots will be long gone by then. I think you stand a chance of finding a spot somewhere along the route, but it'll probably be further back in the crowd. Otherwise, if all possible, I would consider aiming for the second parade.