When we see a very large task we get overwhelmed why? isn't it doable? or are we just making an excuse to avoid doing the task? When we see a larger opponent we get scared why? Are larger opponents unbeatable? Does size really matter? Is size a perfect excuse to keep us from giving our best? I don't think so, if size does matter then why did David killed Goliath? How can Robert Rodriguez (a friend of mine) finish reading a 1000 page book in just 2 days.
We just got overwhelmed by size because we don't want to move and do our best to finish a big task. If we saw how much work is needed to finish a task then we immediately tell ourselves that it is impossible. You see the bigger the challenge/opponent the bigger the rewards. If task is really making you overwhelmed and it is avoiding you to move, dissect it, cut it into smaller pieces. If your opponent is so big, find his weaknesses and spoil it, every person has his own weaknesses and you can take advantage of it.
If the situation is too big just take small steps and that big situation will become smaller and smaller as you progress, never take size as an excuse to stop moving, just keep on plodding, there is no such thing that is bigger than you. There is no challenge that is big enough to make you quit. Size is just a perspective, you can look at it in a different way.