Slowly, is my solution. I do the daily roulettes with them as well as turn in beast tribe quests if they're high enough. If I want to do more than one dungeon a day I just craft or something while waiting on DF. My queue times seem shorter than yours, sometimes I'll have a 30+ minute wait but it's rare and I find I usually get something in 15-20 minutes at the most. I tend to play during peak times on my server so that may be why.

I just accept I can't level it in 3-4 days anymore, though if someone really wanted to do that I'm sure it's still possible if you solo FATE's while waiting for dungeons.