Hi, Rosemary!
I haven't had difficulty getting a great villa at Christmas, Thanksgiving or the 4th of July, as long as I call as early as possible to make my reservations. The key here is that you can book 11 months in advance of check-in if this is your home resort; you may book 7 months in advance at any other Disney Vacation Club property. If I call EXACTLY on that first day of my window, I have far more success than if I try to book even just a few weeks later. In addition, I've ALSO asked to be put on the Wait List if my first resort choice is not available, which has worked in my favor on several occasions. Again, early planning is the key to getting exactly what you want, if you have your heart set on just one particular location at a peak season.
Regarding resale options, I'd contact a Cast Member at
Disney Vacation Club and ask about that, as those rules can change, from time to time.
I know that I can't say enough about how much we love our Disney Vacation Club Membership; the flexibility of the program has been a breeze for us when booking any of our vacations at Walt Disney World Resorts, Disney's Hilton Head Island Resort or even when using my Membership points for booking a Disney Cruise Line vacation. Because we like to travel as a family, Membership was the right choice for us.
Please send me any additional questions you may have about DVC Membership and benefits! I'd love to help!