Check the November calender on the official WDW site to see what time Wishes will be on the night that you're planning to be at Ohana. If it's at 7pm then you'll probably still be in the lobby waiting, if it's at 8pm then you should be in luck. If it's at 9pm, that's iffy unless you have a large, slow eating group. Even if you're in the main dining room, there's a chance that you might not have an unobstructed view, so be sure to put in a request to be near the window facing MK and remind them when you check in at the podium. Good luck!