Long clubs can give a ball enough forward momentum to overcome backspin even with uphill and headwind conditions. As an example:
On a 1st bounce, a back-spinning ball that is still moving forward with enough speed loses all of its backspin due to contact with the ground.
After the 1st bounce, the ball has stopped spinning but still has some forward motion left over. So on the 2nd bounce it starts to roll forward.
This tendency to roll forward after hitting the ground can stop the backspin and even reverse it to acquire forward spin (or forward roll) after a bounce or two, despite uphill and headwind situations. Here is the effect seen with a backspinning tennis ball where the spin is reversed on just 1 bounce:
Another condition that helps this effect is and elevated green, where the ball has not had a chance to drop and lose more forward momentum in its final trajectory.
Happy hitting!
-Keith