I agree, it should be doable and not about fast typing skills. Not a lot more time but a little bit more (so you are still thinking about some, but it is doable on a firs time without memorizing)
Fun! very creative. And as one says above, at some point you get brainfreeze,, the map helps, a little, but when there is less than one minute on the clock your mind goes in panic mode, and you cant think at all anymore.