Excellent responses. Ask the more experienced pilots over a wobbly-pop some night about their experiences in known ice..I am certain that you can learn a thing of two.
In my view, if you have an SOP keeping you out of the cloud below 0 degrees, then good on them. You can always tell the passengers that the safety policies of your company preclude you from flying right now.
I work in EMS, and the live by the mantra that 4 > 1 in all circumstances. (Don't risk your life, that of the crew to maybe save 1 life.)
There will always be tomorrow.