Sorry...someone who knows more than me will have to tell you what to expect from a fuel line that thaws.
You know, the more I think about it, an electric dipstick would at least speed up the car's thawing out, and it wouldn't be a bad thing to have around for every winter. It's regular oil dipstick, except it has a plug. You plug it in to an extension chord, and it keeps the oil warm. My family has a few old clunker cars that would never start in the winter if we didn't keep them plugged in, especially at night. Just remember to unplug before you drive off.
I wonder if there is any way to deliver heat to the frozen spot? I know a lady that thawed a frozen water pipe in her house with a hair-drier. But there are combustible fumes around an engine...
Hope it turns out alright for you. I guess you've probably already established that there is no fuel getting to the cylinders. (To do this, you dry off a spark plug, put it in the car, crank the car a bit, pull the spark plug again, and smell it for gas. I learned this just this week from this forum.)
Parmenides3