I really do hope that the day after the election, Obama withdraws Garland's name. Garland would make a fine justice, but Obama shouldn't let the GOP stonewall for eight months, then confirm Garland just to prevent a potentially better nominee.
As long as Ohio has 15+ electoral votes and isn't consistently polling R+6, it's worth contesting. Iowa less so, but depends on the polls/financial situation. In general, I don't see how one election can cause a state to stop being contestable.