English Teaching in Russia

A British lady is seeking to work at a branch of a company providing English Language Teaching across Russia. She is considerring possible choices of St Petersburg, Ekaterinburg, Rostov on Don, Volgograd, Samara and Krasnoyarsk.
Any suggestions please as to why any of these locations would be a good or bad first teaching post in Russia? She assumes the accomodation and living conditipons will be a matter of luck but seeks advice on the nature and character of these cities and their people beyond what she has read on Wikipedia. Any inside knowledge from residents would be particularly welcome!