Regardless of whether the beers are at real lager temps (say 30-32F) or just stored at serving temps, many standard strength homebrewed beers will diminish in flavor and aroma by 6 months IMO, unless you're brewing in a way that excludes the vast majority of oxygen contact. If you have your process down, I think you'll have better results by brewing beers like these 8-10 weeks before you need to submit, to have clear beer but also hopefully have fresh flavors and aromas. Obviously if you were submitting barleywines or quad, the time frame extends substantially. Just my $0.02 .