I have had good luck with EOs sticking in soap.
Citrus will tend to fade unless you use folded citrus (5x, 10x) and anchor them with a base note like patchouli and/or litsea cubeba.
Some people say that cornstarch, clay, or ground citrus peel helps anchor EOs.
The scent is more likely to hold if you don't gel your soap.
I have EO-scented soaps that have held up well for a year. They're unlikely to have much left by two years.