Similar experience. Way back in high school, best friend lent me his ancient, consistently abused, rusty Toyota Corolla (early 70s vintage). Oil pressure light came on while I was driving, so I pulled over and checked. The stick was dry. Bone dry. Not even a little spatter -- nothing. It took three qts before the oil reached the operating range on the stick! Started car and drove away. That car lasted my friend and his dad several more years.
While the lubricated parts would be better off with plenty of clean, fresh oil, they really won't suffer immediate, catastrophic damage until the pressure drops off -- and stays off.
EDIT: I know, I know, I shouldn't admit this on BITOG, but I occasionally do the "extra quart purge" when I change oil. After I drain the sump, and before removing the filter, I replug the sump, add a quart of fresh oil, and start it. Pressure comes up just like it does with a full fill, and I let it run for ~15-20 seconds, then shut off, redrain, and do the filter. I do this less often now, especially since oil has gotten so expensive. But if I have an extra quart. . . Point is, even with only one quart on board, OP rises like normal. Of course, I would NEVER drive the car this way.