Maggie, it's interesting that you suggested Grizabella's song "Memory" for Susan and then referenced Betty Buckley's version.   The first version version of that song I ever saw/heard (from the actual musical) was that of Susan's ideal, Elaine Paige.   

Grizabella (Elaine Paige) sings "Memory"
Elaine Paige as Grizabella: "Memory" (reprise)