I was about to let in with criticism left and right, given that a lot of you seem to buy into the anti-sugar diabetic mentality that non-diabetics or type 2 diabetics have been running on for the past twenty years, but I figured it would be better to throw in my two cents in terms of existing without insulin, given the requirements to get the stuff, while out in the open.
I'll admit, I've only ever explored. I've never had to remain dependent on only myself, but that being my ultimate goal, I've experimented pretty drastically with my insulin and food intake. The first and foremost is concentrate on what you're eating. Anything that has carbs is going to break down into simple sugars eventually, it's just a matter of time; beans, potatoes, damn near everything. This has already been addressed.
The problem is that you need these energy sources to function and avoid diabetic shock, which is a far more immediate threat than having a high glucose level. Of course, high glucose levels are going to shorten your lifespan, but if you end up in diabetic shock in the middle of nowhere, with very little food or no natural instinct to go into a feeding frenzy when your blood-glucose is low, then you're damn near fucked and should consider yourself dead.
My advise, pack as many starches as possible. If you're traveling, you're going to be burning a lot of energy. You'll need to offset this exercise by pseudo-sugarbombing yourself whenever you can feel yourself headed towards shock, or, if you've been a Type 1 for most of your life, when you can feel the symptoms of a low blood glucose level setting in.
High blood-glucose is a lot easier to manage. Do what you want in terms of eating, but be prepared to pay the price; you're going to have to work off those excess sugars pumping through your system unless you want to end up in diabetic ketoacidosis. Sure, it'll make you skinny for the fall line, but your body will eat away at itself with lightning speed.
I'll admit, I'm young and ill-experienced at living without supplies and the like. I prefaced this schpiel with all of that. That said, I've been a Type 1 diabetic since I was twelve months old, fully dependent on humalog and regalin, before running the small gauntlet of lente, ultra-lente and finally lantus supplemented by humalog. Taking some time off from the world of easy access foods and medication wasn't too hard so long as I micro-managed what I ate. Any time you feel a high blood-sugar or low blood-sugar coming on, act accordingly. If you feel what you've distinguished as your "low blood-sugar" tells, eat something with carbohydrates or sugar, or, barring that, do as little physical exertion as possible until you're able to do such. Should you find yourself feeling any of your "high blood-sugar" tells, do some cardio and eat little more than colorful vegetables or, provided you're not a vegetarian, whatever you're able to kill in order to keep your energy up.