jfk, how are you staying longer than 6 months in Russia? I contacted doctor Barinov's assistant and she wrote that "It may be difficult to stay
here longer than 6 months, as the Migration office has made its rules tougher."
Ok assuming you do the intake and interview in one day and have the procedure done within a few days. Then you need a week after that until you start lengthening.
5 1/2 months is a lot of time to lengthen 5 or 6 or even 7 cms for external tibs.
You should be able to do .667 mm per day. 60mm / .667 = 90 days of lengthening.
Mind you that you will have a consolidating phase to run though but if your lengthening went well you should be able to find a doctor who can monitor your healing progress outside Russia .
This would be my plan of action.