If the outbound is delayed sufficiently to require a refund, you would have the option of a full ticket refund or a refund only of the outbound segments, on a half-round-trip (i.e., favorable) basis. However, in that case, I highly recommend you say something like this: "Please delete the outbound segments and leave the return alone; I'll find my own way to XXX and take care of the details later." Then, do not attempt to get a refund until you've already flown the return. Otherwise, you're likely to get a refund of the entire ticket accidentally.