It is my understanding that you want to be at Pearl early in the morning. Thus getting in late the night before may be an issue with some.
Also, a recent newspaper article showed people getting too close to lava. That may not be an issue with a tour, BUT be aware that there are tours which get you too close to lava and/or the ocean where people have been injured or killed.
In one lava flow, 23 acres (23 ACRES!) of new lava slid into the ocean with no notice! There would be no way to save someone from that.
Please treat nature with respect out here.