I think the whole point is not be be overly zealous and greedy.
The 100% event quest chest box suggests that you only need to clear floor 25 in both pillars, which one Miu would do nicely. The rest of the achievements are do-able so hitting that box should be a medium challenge.
There is no exclusive achievement for clearing all the floors except for the individual floor rewards, which pays out real nicely and in accordance to how much you invest in the game. I felt this is a good move to motivate high paying players to invest more and keep the game going, something like a limitless cap to the event. What I really want to emphasize is, THERE IS NO NEED FOR YOU TO CLEAR ALL THE GODDAMN FLOORS.
I'm Plvl 15 and i'm having a hard time with floor 30 exile. And that's okay since i'm having fun, i believe the difficulty was the developer's intention as i mentioned above and i'm not being sour with lousy attitude against the devs for "Hey i invested so much and i can't beat your stupid event it was so much easier and fun before i see no light now".
Enjoy the event, have a merry christmas and a happy new year!
Yeah I think I'm just being a little pessimistic recently, I should get that checked. Thanks for swinging me back in the right direction

On a side note, how much did it cost for you to get to prestige 15? I've heard rumours about it being 6-7 grand so I'm a little curious. Also, do you happen to remember how many prestige points you had to get for prestige 11? I know it's 5k for 10 but I can't see beyond that so I'm not too sure if I should go for prestige 11 or buy the Boxing Day bundle or just hold onto my money for now.