North Dakota has definitely become way more conservative than South Dakota in recent years, but I still wouldn't characterize it as Titanium R in the same way as, say, Wyoming or Oklahoma.
I thought the Dakotas were basically mirror images of one another. They vote so similarly close in presidential elections. I know South Dakota has a few more Native Americans and North Dakota has the Bakken (not to mention that North Dakota has the highest number of churches/religious adherents per capita than any other state), but I think if South Dakota goes blue/Atlas red, North Dakota does as well.
My list of Titanium Meltdown Trump states would be Idaho, Wyoming, West Virginia, Oklahoma, Alabama, Kansas (not jumping on the #BattlegroundKansas bandwagon because of 2014), Nebraska, and the Dakotas.