I read back through to see if anything new jumped out. Firstly, if you are sure this is the right move for you, then the letter is a good one.
Now, let me play devil's advocate. Your H decides no way the kids leave, then what. You could have trouble on your hands. I am sure you are aware of it.
Next. Your son. I know you said he doesn't want to leave, but that you can't base your life on what a 5-year old wants. Why doesn't he want to leave?
Are you leaving out of far? How far away will you be? I am asking because this is a big move. I know you have said a number fo times that you are done. If you are, no problem. It isn't a bad thing to think things through one more time.
