It seems like a lot of the airlines are not as strict about blackout dates as they used to be.
When I first began using frequent flyer miles, it seemed like I was constantly running in to blackout date problems.
Over the last few years using these programs has become much easier and blackout dates aren't much of an issue. Maybe it depends on the airline or the frequent flyer program.
Any time I have tried to book a flight with a cheaper airline for one way tickets, it seems like there are always a lot of blackout date rules though. I have found that this isn't usually worth the hassle.