I’ve noticed that at small companies meetings and appointments are cancelled and rescheduled more often. This is partly due to everyone managing more things, but also partly due to ease of coordination in the company.
It seems larger companies are less likely to cancel. The coordination required to reschedule is a lot of work from coordinating schedules of all the attendees to finding an open conference room at the time.
If your making a trip somewhere try to anchor it with a couple meetings at large customers (by size, not necessarily revenue to you) you’ll find that at least your odds of cancellation go down.