I think it all depends upon lane width and how long the line of stopped cars is. Often in the DC area, we have gridlock -- the line of backed up cars can extend for miles. Since nobody is moving (or will move significantly for the next hald hour), they present no hazard -- just pass them. This happens a lot when there is snow.
If the lane is wide, so that it can be easily shared by a car and a bike, then I'll stay on the right side of the lane and move to the head of the queue.
On the other hand, if the lane is so narrow that it feels like you are filtering forward, then stay in line. The cars you squeeze by at 12 mph will soon be squeezing by at 40 -- not safe. Best to stay in line. When traffic is moving well, the queues are short and little is gained by advancing to the front.
Paul