Aye! It seems you have been riding a fine breeze and have even secured some gold in the hold. In other words, your patience and diligence have paid off in obtaining a reservation at one of the finest galleys on this side of the Caribbean: Blue Bayou Restaurant.
Regretfully, it seems you may be sailing with a lighter crew. But keep your colors high, for that's merely a small bit of wind out of the sails. To be sure you continue in smooth waters, I recommend letting it drift with the tide. That is, you may simply keep your reservation as-is. If ye've a mind to share the bounty, you might occasionally check if the reservation can be modified to a smaller party. However, since the restaurant has very few tables that seat only two Guests, odds are such a modification won't be available in the system. So it's all clear and steady as she goes with your current reservation.
When it comes time to check in for your reservation, simply use the Disneyland mobile app to indicate the number of hungry sailors in your crew, whether any of your hands have special dietary needs, and if you are marking a fine milestone worth a cheer. As long as you still arrive for your reservation, it will be fine if the number of Guests you mark is fewer when compared to your original reservation. No coin will be needed at the dock. Meaning, you won't be charged a fee for those Guests who got left behind in port. After all, that may simply allow some in the reserve crew, or those who have joined the walk-up list, to enjoy the restaurant too.
May you enjoy fair winds and a following sea on your journey to Disneyland, Laura. We'd be pleased to have you visit us again any time here at planDisney should you come across any other questions as you plan your voyages to the Disneyland Resort, other Disney Parks and Resorts, or, perhaps, a Pirate Night aboard the Disney Cruise Line.
Fair winds, smooth seas, and tight knots till we speak again, Laura!
~Tony