First, set the priority right for your life. Money is not a big issue for you. Don't worry too much how much you will lose or not gain in either choice. Kids are not an issue.
In your situation, the most important is to boldly go where you have not gone before --- to make your life more fulfilling.
As your said, "It is highly possible that I might never move to that level if I pass up this opportunity". Giving it up, you will regret and always wonder "what if" for the rest of your life.
Low-probability worst scenario: you fly back-and-forth each week at your own expense; have to quit in one year and give back the bonus. That totals $10K net loss at most. Then, it takes your half year to find a job at today's level. So what? 你的家庭并不发愁生计. But you have gone to that level, seen and tried -- life is beautiful, isn't it?
