I really recommend just giving it a try. I've DF'd it many times and it's never failed. Some of the fights are a pain in the ass, yes, but ultimately, it is designed to be cleared by randoms so I'm confident you'll be able to clear it. Plus, it's just a plain beautiful dungeon! The new relics are honestly extremely good for the level of investment you need to make as well, so I think they'll be a crucial step in gearing for you.
I did the lighthouse yesterday and that was already horrible haha. Oh man.