I have "my plans", the reservations are shown by day - I can click on "view confirmation" and "show details" but neither takes me to someplace that has a "cancel" option. I do have a "remove my name" option on my two newest reservations.
Some are as close as an 1:05 next to each other - I was trying to get the right times for us. Are they actually already canceled now? I remember getting a warning when one reservation was too close to another on past trips, and did not receive anything with these.
ETA - I can't find a "cancel" button on the most recent reservations either.