I've hunted the Hell Creek area and other places in the Breaks. It will take some patience and get away from the rest of the hunters. There are no guarantees on a big buck period... but there are some around... and they don't get big by being stupid... think about it.
Depending on the weather, your experience can be good or it can be hell, so best to go into it with that attitude up front. Your temps can be anywhere from from sub-zero to 70... dry, wet or frozen. Winds can sometimes be up to 40-50-60 mph. If it's wet, you'll learn what gumbo is and it will make you wish you were back home.
Now, I'm gonna give you some good advise if you're looking for a good buck. Hunt the last week of the season when they're in rut. Take it or leave it. Last year (2010), the last week of the season was snowy, windy, with sub zero temps.
There's a reason Montana is such a great place with so few people.