Yes we can do that. Even though I know what you mean it would be probably a bit boring to drive weeks in real time without any contact at all.
That's why we did it like in Silent Service where you have this time compression feature.
When you are very close to a convoy the escorts will likely pick you up pretty soon. Best is to dive immediately and see what can be done then. Plus you can change the difficulty which has direct influence how big the chance is that escorts detect you sooner or later. E.g. in easy mode you can look much farther than the escorts can. Of course for a chance to use your torpedoes you should get closer than 3000 yards.