Where Marge might go, having run of success? (2,1,4)
I believe the answer is:
on a roll
I believe this clue is a double definition.
'where marge might go' is the first definition.
(margarine might go on a bread roll)
'having run of success?' is the second definition.
(on a roll means having a string of successes)
(Other definitions for on a roll that I've seen before include "Experiencing a run of good form" , "Hitting a purple patch (as bacon might be?)" , "Where registered names are" , "having a lot of luck?" , "spread may be smeared thus" .)