My base light is a Cygo Lite Night ROver...Also have a Nite Rider Digital Evolution...Reason, I would take the Cygo Lite...I have two batteries for it..Each rated for two hours on one beam...So that is four hours...Guess never hurts to take a Compact headlight, just in case.. Oh, touring bikes have lots of carrying capacity. Probably always have a change of light bulbs. THink that is well prepared.
Think I would not like riding in busy traffic conditions at night.