I have only lost consciousness once after being T1 for 11 years (next week!). I'm not sure how low I was, but I'll tell my story.
I was in Utah with a friend of mine, Kory, and we were driving back to Vegas which is where Kory lived and where I would be flying back to Minnesota from. We had skipped breakfast, and it was well past lunch time ( I realize my error, don't worry....

), and so we stopped at a Subway to have some food. Well, we were in the line deciding what to order and such. When I got to the checkout, the room starting getting blue, and I couldn't breathe, and eventually passed out. When I came to, I ate a footlong sub, and some chips and it only brought my bg up to 155. Makes me wonder how low I was.....
Well, that's my story! I haven't passed out again since, and I hope I don't again.