As far as electronics go: I'd add a pocket or emergency radio, try to get a light with a very low power mode to prolong the battery life (you only need about 2 lumens to avoid stepping on someone on the way to the bathroom), and a power source of some sort (solar, power bank, battery charger).

Phone: 1/2 lb with charger (required)
Headlight: 1/4 lb (required)
Pocket radio: 1/4 (sports) to 3/4 (crank) lb (optional. Made somewhat redundant by a smart phone, but not vulnerable to network congestion and with wider coverge)
GPS with charger: 1/2 lb (optional, same reason as radio)
Solar charger (10W) or 10Ah power pack: 1 lb (required)
External hard drive (remember that this is a one-way trip): 1/2 lb (optional. Copies of critical files can be carried on a smart phone memory card)

So figure that a full e-load is going to run from about <2 - 3 1/2 lbs.