I think it’s the Outer Limits episode Inconstant Moon which is about this. The moon is unusually bright, caused by the sun going nova and the people on Earth have hours left to live. Everyone on the day side is already dead and this one dude figures it out. He asks his crush out for coffee and have a nice night together till they die the next day (or do they? No spoilers). Very good episode.

Should the survivors amass bottle caps?

I could get behind this. It would certainly simplify things.

Just empty the fridge and get in. Closed the door. Worked for Indy (Jones).