It should survive, fig trees are very hardy. They are known to die back down to the ground during cold winters, but sprout back.

Height of cut depends on what shape you want. You can can down to a few inches above ground and it will survive (granted you don't let it freeze). Fig production will be reset for a about a year though.

Remember you can root cuttings. 3' prune can easily be 3 new fig trees once rooted.

I like the single trunk but its just too tall to reach the fruit, so I will cut it shorter (when it goes dormant) and hope it survives, we rarely freeze here in San Francisco , and I can always move it ( its potted) into a small green house for shelter overnight . I will definitely try to root the part I cut off.

You can definitely cut the main stem back to any height that you want, when the tree is dormant. I plan to cut about 4+ feet off of one of my Verte figs this winter.

You can root the pieces of what you cutting off. Or you could air-layer off the whole top in early spring, and have a semi-mature tree already. But if you choose the air-layer method you will probably not get any fruit of the parent tree that year. The removed top might successfully fruit.