This is a very interesting subject. I really think its time fireworks should be banned for sale to the public. Apart from terrifying some animals, they're used in many antisocial situations and of course, are dangerous in the wrong hands.
I have two dogs, one is fine with fireworks both the noise and visually, the other is terrified. I have never considered going somewhere in the van around bonfire night as I always thought well, the van has thinner walls than a house.
During the run up to bonfire night, each evening, we close the blinds and curtains in the house, turn up the volume on the tv, have the dog in the lounge with us. That has helped considerably.
I'm with Mel on the psychology aspect, we totally ignore the dog if it gets distressed.
Comfort a dog when its terrified = reinforce the fear
Last year, I went outside and recorded the noise from the fireworks and have been playing it back to the dog over the summer. It appears to have desensitised her somewhat. We'll see as it gets nearer to bonfire night.
You'll have to let us know how you get on.
Lisa