At first glance, it looks like you might need to cast a non-FoF Ice Lance if you're at 5 Icicles and don't have an FoF proc. As the damage in the Icicles is "stored" from FB/FFB/WB, the damage that's stored in the Icicles will be the same amount regardless of whether that extra damage is attached to a FoF or a non-FoF Ice Lance.