if it's 10pm you can make it to the park with a wall to wall packed main street... Bus might be quickest since it's close to whispering canyon but you should have time for the boat (make sure your bug sprayed up, it's a wall of mosquito on the dock at night that you have to walk through (about 50-70 feet long wall).
If it's 9pm. I think your going to get done near 9pm, that place generally takes 90 minutes or more when I go there. your best bet is walk with purpose to the cast member parking lot.
you might want to get 7pm reservations if possible and that changes everything.