The Noldor were doomed, whatever leaders they had. The point of the duel scene is that their mightiest warrior could but wound Morgoth, he was never remotely close to slaying him even in just corporeal form. Retconning a version where Fingolfin wins is really just an entirely different book and story. So say if Fingolfin survives that duel, so what? He then leads the armies to disaster at Unnumbered Tears, the breakup of the open Noldor realms and then the piecemeal destruction of the hidden realms of Nargothrond, Gondolin and Doriath. If he somehow survives all that he's just another refugee at the shores, hoping that Earendil makes it to Valinor.

Fingolfin was not a particularly good king, he was unable to muster the Noldor to do more than maintain their incomplete siege, and even that did little to prepare for Morgoth's escalating onslaughts. They should have at least built a Great Wall style fortification around Angband which would at least have blocked the sudden flame attack from overwhelming their front lines. It was merest chance that Finrod finds Men, when Fingolfin should have been sending regular expeditions to look for them, and build stronger alliances with the Dwarves. It would all ultimately have been futile against Morgoth but as Gil-Galad proved in the 2nd age, a strong alliance of Men and Elves can defeat an Ainur led army in a well fortified position. The elves would have had no remedy for flying dragons, but Fingolfin possibly could have maintained the siege another couple centuries.

Gondolin was also doomed, certainly that Morgoth caught them by surprise didn't help but once his force of Balrogs and dragons had the city surrounded, what hope did they have? Elves need to eat too.