No special election? Ugh. OK, thanks.
Well, the election for the seat is going to happen in 2018 regardless. Presumably getting Manchin out of the seat and a weak Dem appointee (the incoming Governor, Justice, doesn’t have many strong Dems to pick from) would assure the GOP probably picks it up (what I saw, the reelected Rep. Evan Jenkins from the Southern third of the state appears to be the potential leading contender to run). Manchin, if he stays and remains a Dem, is going to be tough to beat, even with the now heavy GOP lean of the state (where Zero in 2012 and Hillary in 2016 failed to win a single county).
The article says that ND is a state that does NOT allow the governor to appoint Senators. Instead, there must be a special election.
A Republican will almost surely win it.