Both (so far) solutions are great and accurate. However instead of having to search for gamers having a marathon, I came across this one account that is currently the only 24/7 stream on Twitch. Leave your console on whenever you don't use it, preferably over night or when you're at work/school to gain some progress. Also, for those of you who don't have a large TV, the snap function will cover up a lot of your own game making this solution slightly better.
The user you want to search for is StreamerHouse. Tune in, turn off your controller and TV and start counting
sheep the hours.