What are the chances of finding an exchange on Interval?

I am exchanging my 2 bedroom summer week in Hilton Head in hopes to exchange at Marriott Myrtle beach or Hyatt Siesta Key during the summer. What do you think the chances of trading will be? My unit is considered Platinum and the Highest TDI.....But trading into Myrtle beach summer at marriott is also the highest TDI. The Hyatt has limited availability but the TDI is much lower during the summer....

The past two years we traded our Hilton Head Summer week for summer weeks at Hyatt Coconut Plantation. We received confirmation via interval in mid- January.

My guess most people pay their maint. bills in Dec/ Jan???