The console command is limitless whether you use it or not. It's already in the game. You have nothing more than your self control to stop you using it, and the same is true if you use it to add capacity (your self control is all that stops you from adding unlimited capacity). As for realism and historicity, let's not go there. Your character could never realistically carry all the crap that he does in the game. If you're suspending disbelief or rationalizing by saying that he has a magic bag or something along those lines, just extend it a bit further. Your magic bag can carry twice as much as before. There's no reason that you have to add a donkey to make it "believable."

Anyway, if you prefer not to use the console, I have no problem with that, and I'm not trying to say that you're "wrong." I'm just not convinced that your reasoning makes sense, that's all. Seems more like a personal neurosis than a rational preference.