I've yet to find a LED lantern that will chuck out > 800 lm(*) for >
6 hrs that a gas lantern will. Not to mention the suplimental room heating. B-)I have a shaker torch next to the bed for the battery reason but it's light is pretty pathetic but enough to get to the lanterns and fire them up (one has piezo ignition).
Saw something in CostCo yeasterday, twin pack of a couple of "nightlight" torches that dropped into a plugin charger unit. I think they did the non-maintained "emergency" light thing along with a maintained nightlight.
(*) More than a standard 60 W incandescent perl bulb.