You have accepted the job in another country. What are the people who are most directly affected going to do?
Your partner will be far more isolated than you will be. You are moving into an office or factory where you will have a large number of people who want to get to know you. Will your partner want to work? Will your partner be able to work without going through a great deal of legal red tape that your company will sort out for you? If they have no work then how will they make friends? What sports or social club or what religious organization will they want to become part of. Realize that some things that may have been legal in the US are illegal in the UK, such as owning a hand gun. Golf may be a good way to meet people but fees are expensive and a vehicle is required to take you to the links.
Children are a far more complex problem. You will need to have your children in school. They will need to be learning and gaining qualifications relevant to your home country and that may be expensive. If you choose to continue their education in the local school system then the question of who they will make friends with can become a major issue. The removal of the familiar and the distance between them and their old friends may be an immense burden for a young person. Family ties may be strained that had been strong. You should be making a plan for visits from grandparents and good friends as part of your strategy.
The whole family may be thrown together far more, especially in the first few months in the new country. Living in a hotel room or rooms for the short term can be part of the price we have to pay for this new posting abroad. The absence of routine and the presence of strange people with you at breakfast in the hotel can be upsetting to a child or children. Better if you can arrange some holiday self-catering accommodation and then you can control what they eat and when.
Strange foods and brand names can be a battleground if the children are not prepared to experiment and find out what can be nice about the new country. Look out for strange names of familiar foods and for smaller portions of what you do enjoy. Be aware of the possible problems before they happen, and then you will find that those who you thought would be affected are not being affected so much.