Until all 3 of you die because you accidentally started an uncontrolled fire while you’re already in an emergency.
2 people and 2 space blankets have just as good odds as surviving the cold than 2 people and some candles. Without needing to worry about fire.
A candle is going to heat up the area around it and dissipate that heat. The blanket will simply keep that 350 btu that you produce every hour much closer to your body, and stop you from freezing to death.
Since you seem to have issues understanding things like basics thermodynamics and physics, I’ll break it down in short sentences.
Candle make little heat that go away into air, take long time to raise temperature of room. Long time means candle likely left alone for long time.
Blanket keep your little heat close to body, keep you warmer than candle will.
Candle balanced on tower of pots and bricks. Candle not likely to fall, pots and bricks very likely to get bumped by idiot trying to use candle to heat entire room during emergency. Idiot might be asleep when they bump candle. Or idiot human might have idiot cat that want to play with shiny glowy candle. Now idiot die in fire cause big fire use all the air and make a lot of smoke.