Thanks, everyone. I did cancel prior to the scheduled date of travel and was told by a UA rep to fill out a refund request online, which now seems odd given this doesn't sound like the correct route based on the nature of my ticket, situation and request.

Thanks for the tips on locating - I now see the trip under the "view all reservations" link within my Mileage Plus acct (not very prominent though). It directed me to a tab with the cancelled flight and an oppty to rebook. Whew. Thanks again for all the info!