Hrrm, even getting to the festival by Day 30 will be tough. Currently it's Day 18 and I'm attempting to take out the Low-Demon (doing this prior to the Young Avian, Ogre Commander, and Bandit Leader may not be plausible, I'm not sure what the intended order is).
I was able to take out the goblin shaman fairly early, but I don't think it was Day 2 (I remember having to at least learn Fire first, and I think I got at least one equipment upgrade). That'd be pretty impressive without Water Skin.
Last time I tried, I can't even take on the regular bandits from behind, which I believe I would need to do to get through the tunnel (could be mistaken). I think I need Thunderbolt first before I have any hope of taking on them or the Ogre Commander, which I should be able to get now (trying to take on the Low-Demon first).
As it happens, Charlotte is a very important buff monkey, since she's the one with Heat Up, which makes everyone else a lot more useful.
In general I try to avoid using consumables unless I have a specific need for them, since I might need them later. For my New Game + run, I intend on going 0 Lewdness and ideally no mental changes.