Of course, a bigger hole can be easily cut and someone can reach it and get the door handle anyway.

 

Smaller hole is less conspicuous and doesn't affect resale value on the parts. Also with a smaller hole, you use a smaller tool. If the tool is small enough, you may have a better chance of not tripping an alarm.

As for cutting a hole large enough for your hand and then reaching to the front of the door panel to get ahold of the lock and/or the door handle is a bit tougher than it seems. Don't believe me. Roll the windows all the way up with the top down...now try to reach the door lock.

 

Smash the window, slash the top, pick the lock from the outside (ok, THIS they can't do on my car. ) If they want it, they are going to get it.

You could disable the switch unless there is power to the ignition. That would be pretty easy and keep it that much safer.

 

I used to have auto roll up on the windows on my other S - and that was a factory option