You have to charge the LED lanterns somehow. Plus they don't do much good when you are freezing to death. At least you can huddle around a burning candle.
The ones I have run on batteries. They’ve lasted us through several years of occasional blackouts without even changing them.
I like the ambience of candles, but I’ve never found a burning candle to give off much heat unless you build one of those clay pot ‘ovens’.
Get a small candle lantern, go into a small closet and wrap your blankets around you (except for your head) while sitting against a wall, with the candle lantern between your legs.
The tent-like effect will warm you up and recharge your internal thermostat.
You can also put the candle lantern into a heavy can or pot, set it underneath a chair or stool, and cover everything but your head with your blankets for the tent-like effect, while you use your led headlamp to read a book, or play cards.