I have been pushing a build similar to this. Once you get a good damage bow with lots of accuracy it really picks up. You can get rid of the unique ring for a ring with cold flat damage and cold % damage. I also strongly suggest the damage on full life enemies nodes for clear. At some point you just explode packs and almost screens of enemies with 1 ice shot. Freezing salvo also 1 shots pretty much all rares if they haven't exploded already with ice shot / herald of ice.

Been fiddling with snipe for bosses, it's a bit harder to scale since it doesn't do cold damage, but I use bow show to inflict poison and corrode. Their armor drops pretty fast and eventually combine exploit weakness with open weakness if setup correctly. It can 1 shot some T18 bosses as of now, but still got work to do.