The below is from Mousesavers: Looks like 3 nights or longer.
Magic Your Way Package with FREE Dining Plan
Check in between 8/21/05 and 10/4/05 for a Magic Your Way vacation package of 3 nights or longer at a Walt Disney World resort and get the Dining Plan added at no extra cost!
Sample prices for a 5-night/6-day vacation, including 5 nights accommodations at a Value resort, 6-day Magic Your Way Base Ticket and FREE Dining Plan:
$425 per adult
$209 per junior (ages 10-17)
$168 per child (ages 3-9)
Other resorts and lengths of stay (3-10 nights) available at varying rates. The passes can be upgraded at an extra charge to include Park Hopper option, Magic Plus Pack option and/or No Expiration option.
Some additional sample prices, showing the flexibility of this plan:
A family of 4 (two adults, one junior age 11 and one child age 9) staying at Port Orleans Riverside for 3 nights, 3-day Magic Your Way tickets with Park Hopper option and the FREE dining plan would cost a total of $1293.
A family of 4 (two adults, one junior age 10 and one child age 8) staying at Port Orleans French Quarter for 7 nights, 6-day Magic Your Way tickets with Park Hopper option and the FREE dining plan would cost a total of $1956.
Disney's Magical Express, providing FREE transportation and baggage transfers between the airport and your Disney resort, can be added to this package.
Stay must be 3-10 nights. Sample prices are based on adult double occupancy in a standard room in Value season. Promotion is only for travel most nights 8/21/05-10/4/05 and the number of packages available is limited. No group rates or other discounts apply. You must book by 7/3/05.
Helpful hint for those who already have tickets or Annual Passes: This package is just like regular Magic Your Way packages in that the minimum ticket length is only ONE day! So you could even book a 10-night package with 10 days of FREE dining plan and a 1-day ticket. Because of this, it may be worthwhile to consider the Free Dining package even if you already have tickets.
Thanks to Small World Vacations for info.