It could be a bit of a hike, but everything could change between now and Saturday. I'll be there when you are, by the way. You can ask at the visitors center before you take the long drive to the end, but take what they say with a grain of salt because conditions change quickly. Depending on your group, I recommend going to the end of the road in the mid afternoon. Then you can decide if you want to attempt whatever distance hike you have. Even if you don't do the hike, the current flow id likely to be glowing and visible as it gets dark. Bring all the water and flashlights and such suggested by the NPS just in case. Also, bring binoculars to get a better look at anything glowing on the mountainside.