Yes, and let them know you've prepared

After a couple minutes' trekking you decide to speak up. "Actually", you say, "I have a plan to retrieve Rosie with minimal harm to myself, and I've packed extra supplies in case something goes wrong." Before your father can reply you continue "I think this is the best and safest chance to find her and get her to safety. I can also use this as an opportunity to get a message from you to Reverend Fields"

His reply isn't exactly pleased. "If you say so. Try to be at the compound by dark." To emphasize the point he turned on the radio, or rather, pressed the button and nothing happened. "If he has what he needs to make the journey let him join, otherwise tell him to hold tight until tomorrow."

You're not sure if it was the preparedness or the mention of the preacher that led to his assent, but after the first mile or so is up, you break off, and find your way through the winding labyrinth of suburbia to the church, with the attached house off to the side.