> "...immediately realize that which will make it more difficult to modify these functions". Please clarify what you mean here.

I absolutely would prefer a method to look like:

def main():

  SetUp()

  try:

    DoStuff()

  except:

    HandleErrors()

then a thousand-line god function. It encourages modularity, reduced state and scope (please ignore my example above which implies a lot of shared state:)), and every method should be well-named and do a single thing well. Maybe for super-sensitive realtime systems, this might cause a few necessary checks that we could ignore, but we are talking about readability here.

Having to navigate between different methods is honestly a really lame excuse for sticking everything in one method. That's what IDE's, documentation, and good method names are for.