One of my friends has type I diabetes, in more than one times, she needed urgent visit/call to her doctors just to get the medicine she has being taken for years.
with that said, as a type 1 - if I was in a predicament you bet i would go, if i recall they sell it for 25 a vial, whereas a vial of normal, fast acting insuling is ~250.
*usd
Walmart sells Novolin R/N for 25$ a vial without prescription. In all but three states I think, it is legal to purchase veterinary needles.
Novolin isn't probably as good as what you've been prescribed. But it will keep you alive.