MNSSHP and leaving the park

I have a 7:00 pm reservation at Whispering Canyon Cafe on 10/6. We will be at MK and its a party day. What time should I be at the boats to get to WCC? I’ve read that it’s crazy leaving MK after 5:00 if you aren’t going to MNSSHP.

It is a quick boat ride but I would be leaving between 5:30 and 6:00.