Example:
We have a February UY and often travel to Hilton Head over Thanksgiving. (That goes directly against UY philosophy)
Anyway...we had our nice little trip planned for late November, and then my Dad got sick. He was in and out of the hospital from the first of October, so we kept our fingers crossed. At that point, nothing had been so serious to keep us from going to Hilton Head. (6 hour drive)
So by the week of our trip...Dad was at death's door, and had to have emergency heart surgery. The hospital had to bring in the surgical staff on the Saturday after Thanksgiving. The doctors were using words like IF he comes out of the surgery.
Needless to say...no Hilton Head.
We rescheduled for MLK weekend in January. That week wasn't good either. It went to 13 degrees in Hilton Head. We knew it was going to be cold, and went anyway. "A bad day at Disney is better than a good day at home." By this time, we had no choice...use it or lose it.
Long story short...things happen. Sure, on occassion plan something at the end of your UY, BUT if you want to go every July 4th only -- please don't choose an August UY.
PS, Dad is doing much better.