I haven't seen the movie, but it seems to me that the guy wanted to start over with his ex-girlfriend. He walks around with nothing but her number, creates this story hoping she will start over with him.

He may have screwed up when with her, and now thinks this is his only chance to get her back - pretend he is not the man he used to be.

Is his relationship with the former girlfriend explored in the movie at all?

It does sound like the LW does not want to go. Which is fine. But before telling her "Don't Go!" and affirming her worst fears. Why not suggest she try something out first.

I'd propose crunching some numbers. Is there a salary and benefits package that would make the move worthwhile to her? Will her company be willing to pay relocation costs (i.e., realtor fees for the house, and realtor fees, moving fees and closing costs for a new house?).

Also, is the company willing to give a substantial cost of living adjustment.

If none of this is forthcoming, she will be armed with something to take to her manager. She now can make a business like decision and claim something to the effect of "I've analysed all the numbers, and it just is not worth it for me to relocate. This promotion will actually be one step backward, rather than ahead, so while I'm flattered and appreciate the vote of confidence in my abilities, I will have to decline this offer." Something like that.

Otherwise she will have to explain her intuition and reasons for why she would like to stay in hre current neighbourhood. Her manager make think less of her because of this. I think they, management, would have to respect a "business-like" decision - though.

Who know, her company may decide she is really the person for the job and throw a huge compensation package her way.

Mr. Tennis always pulls through. Great advice. Nothing more to be said, really.

After reading the letter one more time, I think Eugene Skinner (posted a coment on page 1) is on the right track.

This has to be someone's idea of a creative writing project. I'm not so sure the letter is real.