<< Resupply or rescue would be out of the question >>
Rescue perhaps. But re-supply isnt that big of a deal. I think it would be possible to send out an unmanned craft full of supplies to orbit Mars. Once the first manned flight arrived a while later, they could rendez-vous with the station.
I'm no astronaut, but that seems feasible to me.
As for not being rescued...well, it's a high risk trip, everyone knows that. The rewards are worth it IMO.