when i was there i found that the big outfitters were very rigid in regards to rescheduling.
on the other hand the small outfitters were more flexible and accommodating, because they can just take a bigger plane or rearrange flights...
If they're the ones cancelling, it's up to them to reschedule you as best as possible. But yeah, the smaller guys are way more pleasant to deal with.
The biggest operator in town yelled at me and slammed down the phone when I dared ask if they'd give me a discount when booking 25pax at nearly $1000 each. So yeah, they're just a delightful company all around.