One thing I realised very quickly is that Russians take their vehicles everywhere - on road, off road, pavements, up and down the most precarious looking slopes. In the city, don't be surprised to have to get off the pavement because someone wants to drive along it, or has already parked across it.
Yuzhno-Sakhalinsk is connected to convenient airline routes from US: weekly flights by Aeroflot, "Reeve Aleutian" and "Alaska Airlines" Y-S - Anchoradge - Seattle and Seattle Y-S - Khabarovsk - Los-Angeles
The Island just right up above of japan Hokkaido. You can sccess into this island by plain from May untill Sepetember. Transit from Aomori or Hokkaido Chitose Airport then continue your flight for 2 hours or less.
or you may access into this Peninsula by ferry from North-East coast of Hokkaido - Kotaru. Remember, this is much relate to the season as well. The ferry only operate from April till Sepetember of every year.
There are everyday flights from Moscow to Yuzhno-Sakhalinsk by the various companies: Transaero, Aeroflot, Vnukovo Airlines, Domodedovo Airlines, SAT, etc.