I have an older gentlemen friend, a Florida native, who after retiring regularly traveled to Ukraine to teach English, mostly to younger Ukrainian girls. He liked it so much he kept going and kept overstaying his visa. He was giving free lessons because he didn't need the money and had been living off his U.S. pension.
The way he was describing it sounded like he had found a slice of heaven. I can't say I'd do the same because I need the money and I have a feeling teaching rates in Ukraine/Russia would be far below what I'd be willing to accept