Well, if you can't use vault then you have to find a taxi - a player that would jump up to the bosses' doors really quick for you but doesn't take any part in fighting them. I wonder why you can't use vault. Isn't it mandatory for something that needs to be done as quick as possible? Otherwise you could use smoke screen - displacement but then you need a good density and huge pick up radius for globes to refill discipline with a blood vengeance passive. It would work for rifts though.
Upd. Don't forget to put on illusory boots because every single mob can simply block you and put on a lot of resource cost reduction because smoke screens cost a lot of discipline. I'm afraid you'd end up with some hybrid-support build in that case and you'd have to swap to your dd gear before encountering a boss right beside their doors but in fact, the whole smoke screen run+ killing mobs would eat up most of your time that you should be spending running to Adria or Malthael instead. Just use Danettas' with vault or find someone to help you.