Late to the rodeo as usual ... first, grats to you and the rest of the family on the new addition.
Second, I will refer you to nursemike's warning about advice from a well meaning soul with no uterus, more of which is to follow
. So here goes:
Add some saltine crackers to your food stores, they can help with the nausea and provide a needed food energy boost. For that matter, DW swore by plain salted potato chips for nausea when she was pregnant with DS. Any salty snack can help, so pick your favorite, but keep in mind this trick may not work for all the ladies so YMMV. You might also add something in there to help give you an energy boost as long as it is safe for the baby. I was thinking maybe some caffeine gum or mints but these may not be safe for the little one. The boost meal supplement or other food may well do the same thing anyway with no worries for the baby.
While it is good to be prepared for the possible bug out (or get home) scenario if needed, I would try to focus these plans on simply getting to the closest safe place to continue bugging in. I guess this is the obvious goal of any bug out plan, but my point here is that you don't want to be bugging out on foot 7 months pregnant with a 50 pound pack on your back. I did notice you plan to trim down the pack weight as the pregnancy progresses, but this all brings me to a final point.
Finally, keep your plans reasonable and within your limitations. As much as you may want to believe you could travel X miles with a Y pound pack on foot if you had to, you may very well find yourself unable to go half the distance with half the weight. You might be MUCH better off planning to make your current transportation more dependable, parking in areas where your vehicle will be less susceptible to damage, or planning for alternate transportation over the distance(s) you might expect to have to travel. In the event you have to travel on foot, I would think it is best to keep the distance you have to travel as short as possible, for your sake and the baby’s sake. Instead of a GHB getting you home, it might be better to get to the hospital, or to a family member’s or friend’s house that is close by.