I have normal SUB protection, I can always say NO.
If it happens pre show time, I have until show to Say NO (if I know about it)
If I don't know they've cancelled my trip, I have until they notify me to make the OTP call.
But even after show, and after acknowledging the notification of, I can always say NO. Really don't want to do that Seattle AM out and back w/no ramifications other than the necessity to find another day of work.
Preferably on a much better weather day and a much easier trip