Welcome to planDisney, Shannon! I'm so glad to be able to answer your question today.
I totally get the goal of stretching that
Dining Plan. Here's the thing to know: your Dining Plan is tied to your
Disney Resort Hotel stay, not your tickets, so it only activates on your check-in day and stays usable through midnight of your check-out day. There isn't a way to tap into those meals or snacks before you've actually checked in to the resort. Since you're staying with family on January 4 and checking in on January 5, your dining plan will begin on January 5.
The good news is you can still have a great first day in the parks! Just pay out of pocket for that day and then switch to your Dining Plan on January 5. This is a great opportunity to try some of those lower-priced snacks like popcorn, pretzels, and ice cream, and save your Dining Plan snacks for higher-priced items the next day. If you want to budget Dining Plan-style, consider grabbing a
Disney Gift Card ahead of time and using it on your first day. It keeps that prepaid feel of the plan!
I hope this answers your question, Shannon, and please let us know if there's anything else we can do to help you plan your magical vacation!
Jessica