I don't know the accurate answer to this but I would assume if your work is wanting you to move they will facilitate healthcare where you are going? It is certainly something you need to know, I am sure you are under regular surveillance in the UK and you would need that as a minimum if you were abroad. But of course, this all depends on where you are going and if there is a reciprocal agreement.
This all sounds very exciting for you and I hope everything goes well -you are showing there is a life after a cancer diagnosis!
