Il ne me restera plus qu’à prendre mon sac.

For me this sentence seems awkward. Il ne me restera qu'à prendre mon sac, should translate: all I will have left to do is take my bag. ne. . . . .que = only which is a fairly common phrase in French. From the lesson: You can also use any of those with ne ... plus (not anymore): plus jamais OR jamais plus, but ONLY plus rien, plus personne, plus nulle part.

Yes I must say that I agree the sentence would be a lot more straight forward if 'plus' were omitted. However in the writing test in which I first saw this sentence (Week 21 - B1 I believe) it was present, which is exactly what prompted my question. I'm aware of the double negative combinations presented in the associated lesson, but unfortunately that lesson didn't offer any guideline at all on the use of ne...que with a second negative, or even if such a construction were possible. Had that information been provided I sure I wouldn't have need of further clarification. Forgive me but this question had remained unanswered for almost two months so I'd mostly given up on a response. Thank you.

Pas de problème ! Je ne me joins qu'il y a 4 jours et je ne fais pas partie de l’équipe du site. J'ai vu que ce qu'il y a eu un peu de questions sans une réponse. Alors. . . Bonne chance.