Both are great cities, but there are quite a few differences. Fargo is much larger, metro area 250K and just a few hours drive to MSP. Bismarck is much more isolated, but topography is hilly and not flat like Fargo. Winter is cold in both places, but Bismarck can get much warmer in those months. In the summer, Fargo can get very humid. I grew up there, I know. Politically, night and day. Fargo is much more liberal and Bismarck is in deep red territory. Fargo has a huge college population in the metro,(22k) Bismarck not even close. Remember, Fargo borders MN-Lots of lakes within an hour or less. Fargo has a lot more to offer with sports, concerts, food options...etc..Why don't you visit both cities in January and maybe you will get a better idea