I just found Sir András Schiff masterclass. This is one of the best masterclass of this impromptu. I've never been playing by thinking the first part of left hand melodies are Cello and Horn... He brings up different voices, lines of melodies (not every note equal), harmonies in each hand and key relationships which is characteristics of Schubert.
Since several fine pianists in GMG play this piece, I think you will enjoy this.