Seed can be refrigerated for those species that benefit from a period of stratification, just as Mother Nature does. Seed can also be frozen for some years, but there is a decrease in its viability over time. You'll need to see what type of azalea you have but my guess would be a period of 2-3 months in the fridge should be sufficient for most if not all azaleas. You can also sow them in winter and let nature do it's thing. Good luck and let us know how it turns out.