I have been away for more than a year now and really want to pick up the game again. Last time I played I had a dedicated coop partner with whom I managed to do pretty much all legendary quests even if they were pretty challenging even when playing in coop, but now I am kind of worried about being unable to do any of the high level content solo and hitting a brick wall. Has anything changed in the last year or so? Will I be able to progress solo or is this game supposed to be played strictly in coop?