You could do that by banking and borrowing. For instance, you bank your 2007 points into the 2008 use year. You can also borrow your 2009 points into your 2008 use year. In that way, you'd have 480 points available for a trip in 2008.
Now, as you said, that'd consume three years worth of points. There's really no way around that.
You need to look at the
point charts, figure out how many points you'd use per year, on average, and buy a contract with that many polnts.
Since you mentioned trading out to Wyoming, I'll add that most
DVC members use their points primarily at the DVC resorts. You can get a week in a 1-bedroom villa at OKW in the cheapest season for 160 points. That's for 4 people. So, you get a lot more out of your points if you use them at DVC resorts.
If you see yourself trading out a lot, you might want to consider another timeshare. There are other really good timeshares out there have a lot more locations, and cost a lot less than DVC.
Basically, DVC is intended for use at the DVC resorts at WDW, Vero Beach and Hilton Head. That's where you'll get the most value for your dollar.