If you're using gelatin, it works best closest to freezing temps. So you would dryhop BEFORE adding gelatin in the secondary. Cold crash to the 30s before adding your bloomed gelatin solution. Wait another 2-4 days then bottle/keg.
I have done this quite a few times and hop quality was not affected. Some people will however tell you that they bind to the gelatin and drop out, but from experience, I have found that this is not the case.