@Cannoneer,
The question is one of capacity. I do not see other facilities available to them. How much can they move if they lose Sevastapol and can the rail and port lines enable them to keep an army in place in Georgia over the Winter if they do not have the direct rail link? Postulating that some unfortunate event deprives them of the direct rail line between Sochi and Abkazhia. It seems a very fragile logistical chain for them to depend on after the mountains get snowed in.