It must have taken a long time to work this out. The story almost reads like a movie, or television show. From beginning to end you cover all eventualities. You explain how each step is accomplished so readers will believe it.

It is true that people like happy endings. Unfortunately, that's not life, is it? Your ending is fine, but I think you should feel free to write the ending that makes sense to you as a writer. I personally accept unhappy endings (as long as they are not violent😃)

I admire your energy in writing such detail. Great use of the prompt also.