I've often retreated from a feral and back to base. I'll climb up the ladder on top of a storage building (my base is the loch and keogh). It's pretty cool to see the other survivors at my base form a firing line and open up on the feral. Sounds like chinese new year! Haha. They usually bag the sucker in a few seconds and then it's all clear and back outside base. It cracks me up sometimes, I traveled maybe half a block, and I've used up all my fire, most of my ammo, meds and snacks. I'm just like damn! Can't make any headway. Haha. That whole area is thick with zeds.