Episode 5 might be 102 minutes which is 1 hour and 42 minutes, personally i was expecting it to be 60 or 70 minutes because of how quickly it came, 1 hour and 42 minutes is a good length.
Heres the proof on why it might be (credit goes to @Dionn)
Hannah Rutherford tweeted this
After playing The Walking Dead Season Two Hannah added 1.7 hours to her Steam Profile Since achievements arent up we could not base it on that, when they come up we will be able to which is much easier.
Episode 4 was only 1 hour and 39 minutes, so this longer it seems.