Are you doing/have you tried closed transfers to the keg?
How long before your IPA's fade? Mine are about 2 maybe 3 weeks tops. I plan to try some ascorbic acid and/or maybe some of the LODO type stuff and see if that helps.
I've been using ascorbic acid at kegging on hoppy beers (though I may start doing it on all beers), and it seems to definitely extend the aroma life. As long as (as we mentioned) you dry hop clear beer and don't let the yeast drag half of the hop oils down, of course. Just anecdotal, but I feel like I get an extra couple weeks of hop aroma using ascorbic. Then when the aroma dwindles (being a keg hopper anyway) I add more hops to the keg.
Edit - Looking forward to a Brewtan B IPA/APA kegged with ascorbic.
I do keg to keg transfers, but I use buckets and don't closed transfer out of the bucket.
Cut the outpost? I envision keg to keg dry hopped beer to be quite the PITA/mess/something getting clogged if you're using a screen. Maybe it's not too big a deal. Also, the waste of 5G of sanitizer and use of CO2 just doesn't jive to me. Fairly certain the pros are not kegging this way either...
That's encouraging about ascorbric acid. A few weeks more would be perfect. I will say polyclar in the boil does a fabulous job extending the life of beers that aren't dry hopped. Absolutely no hop fade on PA after months. The clarity is a whole other level too.
To get us back on topic
(sorry!) I do find that low temp whirlpools do seem to lock in aroma longer and the age slower than a dry hop but the overall effect is reduced compared to the dryhop on bright beer. Probably the yeast interaction and aroma getting carried out the airlock...