You read it here first.
The Republicans do nothing pending the results of Nov. 8.
If the Republican nominee wins election then the Senate continues to do nothing until after the new President selects his nominee in January/February. I see as highly unlikely the Republicans winning the Oval Office and losing the Senate at the same time. That's not going to happen so ignore it.
If the Democrats retain the White House then we have some game space.
If the senate is left in Republican hands then the Republicans will move to confirm Garland before the 114th Congress ends on Jan 3, 2017, so they won't have a greater fight on their hands from an equally qualified but less politically palatable nominee by the new President.
If the senate changes to majority Democrat then I expect the Senate Republicans to try to rush a Garland nominee to confirmation before the nomination can be withdrawn and the new Congress comes into session on Jan 3. and the new Democrat senate takes its place.
Here's the ego question: Does Obama withdraw the Garland nomination Nov 9th, leaving Clinton to name her choice? I think if the senate changes party the pressure to do so will be quite strong.