Migrating Spouses

I know a woman who is letting her husband go and do a degree in Russia.   They both currently live in London. This degree is four years! becuase its cheaper obviously he is going there. I'm baffled as to the fact that her husband will be coming home each summer to see her. Is that quite normal in nigerian culture? would it not be better to save more money and/or borrow some instead of leaving your wifey and kids to go to Russia for like eh four years? is that not a form of seperation?