Best answer by Dinh
@Jll : Unconditional call forward is better, as your line is totally offline in your case.
If you are using call forwarding, I would suggest you get the $3 call forwarding add-on. Otherwise you would be charged at the payperuse rate for call forwarding.
By the way, you could also take your SIM off your iPhone and use it in another phone. You wouldn't need to setup call forwarding.