My solo end game goes like this: I want to setup base, have my own car and then find plenty of weapons and supplies to go south and equip new players - I feel this would keep me going and enjoying the game, possibly even a taxi service to help those without means of transport. The trick is not to get shot so possibly give out guns without ammo and then dropping them off and telling them to loot a certain body for the ammo and by then I'm gone....