Exactly, and the problem with this is that you must purchase at least a 2 day park ticket with
free dining. That means that you would need a ticket for the first few days of the reservation and then another ticket once free dining starts.
Two ways around this:
1. Don't go to the parks (right...like this would happen. I can't get within 50 miles of WDW and not go to the parks)
2. Purchase a ticket for your full stay with your first reservation and use that ticket for your entire stay (both the 1st and 2nd ressie). Save your room key with the two days worth of tickets on them because they don't expire if you haven't used any of the days. Then you can use them for another trip and upgrade them to however many days you need for that trip.
We did the a modified version of the second option for our Thanksgiving trip. We checked in the last day of free dining which went for our whole stay, but since we have annual passes, we just didn't use the two days worth of tickets on our room keys. We'll save those for a time when we only go for a couple of days, or use the credit from them for a longer stay.