If you have to cancel an entire event for some reason, we think that the best thing for your business is to notify customers of the reason, and give them an opportunity to reschedule or cancel, rather than canceling them outright.
This gives you an opportunity to send them an explanation for the trip cancellation (rather than just "here's you're refund"), and it allows you to try to reschedule them and recoup some of the loss.
We've designed our workflows with this in mind.
Here are the steps we recommend for an event cancellation:
Edit the event and set the "public availability" to "cancelled due to weather" or "blocked from public". This will prevent new customers from booking on the trip.
Email all of the customers at once using the "email customers" tool on the event detail page (see screenshot below). We recommend explaining the reason for the event cancellation, and asking them to let you know if they'd like to reschedule to a different event, or if they'd simply like a refund.
For customers who don't reply, you might want to follow up with a phone call.
Add a "private note" to the event, indicating that the trip was cancelled for weather and that you've notified the customers.This will serve as a reminder for you and make it easier to find this trip later.
Based on the responses you receive from each customer, you can reschedule or cancel each reservation as needed.