There won’t be any repossession, but the economy will be constrained. Already the national power company is warning of blackouts because they cannot purchase fuel (the government set rates so low that the power company cannot pay).
International trading partners are demanding cash up front and security bonds for work contracted in Greece, fearing that Greek courts will not honor contracts denominated in Euros. Once default comes, Greece will be much, much poorer. Default only brings mild temporary relief.
Without imports, Greeks will ride in donkey carts and eat grass.