Are you a gambler? Do you have a little flexibility on your return?

Many airlines will let you change the return date on an award ticket as long as you don't change the itinerary.

If the saver award you want is available on your departure date, you can book it with any far-off return date (within the tourist visa stay limits of any country you might visit). Then monitor seat availability for your feasible return dates. ExpertFlyer is a good way to do this: you can set up e-mail alerts when the fare class you need becomes available. The chances are excellent that something will open up as your return time frame approaches and airlines can refine their load estimates better than they could earlier.

If something was 100 percent certain it wouldn't be a gamble, but the odds in this case are way in your favor. Worst case is you have to buy a return ticket, or use more miles for it.