A skilled pianist has a definite advantage over a not-that-skilled long-fingered pianist. I thihk the biggest stretch in the left hand is an octave. In the right hand, there is one chord that spans octave-and-five-twelveths.
Are you trying to practice too fast? I did once and it sounded...full of crap. Speed is almost the last thing you want to worry about (believe it or not) on etudes like these.
Are your muscles trained to move to the right fingering when they`re supposed to? Or do you have to think about every turn you make? Play it enough that you can hold an iced cream cone with your right hand and play the left hand at the same time.
Don`t be mistaken. The left hand is not dead. If you look at the articulations and the slurs in the left hand, you`ll find that it sounds sorta like a harp. Uuuuuppp and dooooooown. LOL! I hope you get the idea.
Is your piano extremely light(Yamaha concert grands) or extremely heavy(Samick World series verticals)? If it`s extremely light, then you have to control the velocity that the keys go down more. If it`s extremely heavy, don`t play with cold hands (that means warm up) and control the force of the keys going down.