Typically, though, most Type-2 diabetics don't "need" insulin, or their medications, to survive. They get blood sugar just fine. It's the complications of being too high that their medication is for. With these folks, the sugar is there, their body can access it, but it can't use it "well."

Going without your pills for a couple days won't do too much damage (no more than their years of unhealthy habits of done, certainly). Assuming, of course, that you don't go into DKA or HHNK.

Now, insulin-dependent is a different story. Their sugars tend to stay high too w/o medications, but they can't utilize the sugar, which is where they get in trouble. Without insulin, the sugar can't get out of their blood and into their body at all (there are exceptions in particular organs, but that's a generalization)