On a similar note, someone mentioned in another thread sometime back how he runs warm water from the tap over a bottle for a minute or so before opening it if the fridge temp is too low for the style. I've done that several times with HB IPAs and they do indeed taste better that way. Hop flavors and aroma seem to come out better around 45-50F, while most fridges run significantly lower than that.
The other possibility is that your IPAs just aren't holding their hoppiness in the bottle. Serving temperature isn't necessarily the only factor in your underwhelming IPAs, time is also a significant factor. Keeping an IPA as hoppy as the day it was born is a question that brewers at all levels deal with, but homebrewers have a much harder time than professional brewers between techniques, experience, and equipment, and among homebrewers, bottlers have a much harder time than keggers. Oxygen is the biggest culprit and when we bottle on a homebrew scale it's really difficult to keep out oxygen like the pros do on their closed systems or even keggers do with their ability to purge their kegs with CO2. One option is to absolutely slam your beers with late and dry hops, making up for the flavors and aromas that age out all too fast by making a beer that's still hoppy even after 75% of those aromas and flavors have dissipated.