I would not comment on how she feels. You can validate how she feels and let her know how you feel and observations/comments from the kids. Don't try to convince her with facts, logic doesn't change feelings (so no link to divorce stats on kids).

Make sure you are not doing this because of how you are feeling right now. I agree with Alex, that note reeked of trying to control the sitch. People who try to control are usually very insecure inside (that's why detaching is so hard during a time when you are crushed inside).
Get your emotions under control, re-read and rewrite. Make sure you can articulate why you are not going to go on the vacation. Do you have to send a response right now?
Listen carefully for her trying to tell you - how you are/think/feel/believe in response. You not getting pushed around is a challenge to her "control" so be prepared. Know the boundary are don't let her cross it. It's healthy for both of you and she will respect you for it.

Cheers

M22,H45,W45 S21/18D12
Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.