2020 is how far his contract goes, but we all know that doesn't guarantee a coach his job until then - just that he will be owed salary through that year. Keep going 4-8, missing bowl games, etc. and a buyout becomes a valid topic of conversation before 2020.
Found in Wiki - "The Bison are the current three-time defending NCAA Division I-FCS National Champions and have a 47-2 record since the start of 2011, the best record in all of Division I Football during that time frame and one of the best in NCAA Division 1 history. Currently, the Bison have won 27 straight games, the longest streak in FCS history and have not lost a road game since 2010. In the final AP Football Poll of the 2013-14 season, North Dakota State finished with 17 points which placed them at #29, the highest in FCS history."
Klieman might be looking to move up and out of Fargo.