I feel your pain. Sometimes there is no problem at all; other days I wonder why I even try to plan anything that will take me away from the house. DBF is afflicted as well, so orchestrating a day trip can be a chore for us. Sticking with a weekend schedule/routine that mirrors his workday schedule seems to help him.

For me, the only thing that seems to make it more predictable/livable is avoiding my trigger foods and eating sensibly the night before and the day of a planned ride. No huge meals, no rich foods.