Long distance moves are harder on families who are used to supporting one another – you'll often find that your phone bill increases and that you'll have more problems adjusting if you're moving away from familial support – if you're moving TO your family though, you can be sure that things may get easier – if a little nutty. Moving back to one, or both families guarantees that your life will probably be filled with help – or interference, depending on how you view your family's input – either way, its worth it, once you find clear and consistent boundaries.
The move itself should be planned the same way as you would any other move – but remember, the more you're moving, the more petrol you'll need. A 400 mile move MAY end up costing you the same as renting a van in the UK – a move out of the country may be cost prohibitive, and it may be easier just to sell everything and start fresh when you get there.
A long move such as over several hundred miles may also change schooling arrangements, or your job – uprooting over a distance of hundreds of miles can lead to new opportunities – or the loss better ones back where you were – so you have to carefully evaluate what you want from your life, and whether it would be best served by moving to a whole new part of the world.
Moving to a different country or continent may leave you with language to consider – do you speak the language that is predominant there – and if not, can you learn it? If you can't communicate, you'll find it harder to do many things we take for granted.