I am pleased to report that our window saga has a happy ending. The guy we got our windows from was very understanding when we explained our predicament. He still had a half-dozen windows left and let us trade for a smaller one. So we don't have to look at this forever.
It did not take long to install the second window
And the garage looks a lot more complete. In fact, these windows don't look like they belong on a garage. Our neighbors probably think we are converting it into an apartment.
We still have to trim them out with 5/4 board. Maybe tomorrow.