Just so you know, there is a special circle in hell for people who cancel on their relatives who are members within that 30 days without really really really good reasons. We have threads that go on for pages, most members will not extend the invitation again, etc. This can be a REALLY BIG DEAL.
What I'm saying is that if this is a real emergency, most of us will understand and work with it.
If this is a "we decided we'd like to take a different vacation this year" or "we overspent on something else, knowing this vacation was coming up and are now cash strapped" you might want to brush up on your Dante.