Hey! According to your calculations you plan on 4 hours on your laptop! Thats not camping! :-)
I did a bunch of calculations myself, mainly when we were using a Koolatron (big mistake), and considered a solar panel.
In the end we ditched the Koolatron and figured we were fine without the solar panel (keep it simple). Yes indeed.. we are good for at least 4 days of camping with our 130RC deep cycle marine battery before charging, most likely could last 6 days.
My calculations can be found at http://campadk.com/pjsnoozer/pjfeatures.html
I think we use the most juice running my two strings of Coleman Xmas lights more than anything (approx 3 hours each night). Galley light maybe gets 2 hours of use at night.. if that. Cabin light 30 min maybe at night. Galley radio about 4 hours. Heater... rarely use it. In cabin DVD player... about 1/2 hour each night (we end up falling asleep by this time).
Worst case, upgrade your battery and you'll be laughing, and without the hassle of totting around and hooking up a solar panel.