I'd have thought that after Moment Musical No. 4, the nocturne should be nothing for you! Just try it and see how it goes as the sheet music looks readable enough.Someone else please comment below and don't take my word for it as this isn't a very good post.
If you can play the chords and octaves in the Rachmaninoff g minor prelude quickly and nimbly I see no reason why you'd have much issue with Chopin Op. 48 no 1, it's tricky yes but not THAT hard. I think I would have struggled more with the Rach than the Chopin at the time I learned the Chopin. The biggest difficulty with the Chopin are musical issues.