Originally Posted by
robb
To be clear: if asked, I would not volunteer that you don't intend to rebook the flight. You simply aren't sure when you will rebook it.
I was in the OP's position a few months ago. I needed to change the return flight of a cheap ticket to an earlier date, and the $100 change fee plus refaring would have been more than a one-way ticket on HP/US. So I booked the one-way (and got MP credit) and a few days before the original return flight I called UA to ask them to cancel the return leg, telling them I just couldn't take that flight. They said "no problem" and said I could use the value of that leg within a year on that same route with a $100 change fee. No one asked for refaring the RT into a one-way or anything.