Doors won't unlock with fob or mechanical key

If you can get the hood unlocked somehow (getting to the cable by removing the plastic panels under the front bumper cover, maybe tilting the front bumper cover up by popping out the sides you can get to the 12V battery terminal inside the fuse box with a charger. If your charger is like mine (6 amp), the accessory battery will probably be pulling too much of a load for a while, but eventually you'll be able to use your fob.