Hey- I want to thank everyone for these really thoughtful and useful responses to my question- I really appreciate it.
I had not thought of applying the miles to my FB (or AZ) accounts- I fly on both regularly and can always slide my AmEx membership rewards points to those carries. That seems to be my best option.
And a few of you make a good point about just making Diamond and dealing with being Gold the following year. . .it's always fun to move up, but never pleasant sliding back!
Thanks again everyone for your time.