The ants are inside my computer and they are up to no good

That’s at least a helpful-sounding answer. The asker didn’t respond with a negative result so perhaps one can assume it worked.

I makes me wonder, though: what’s the lowest temperature an ant could realistically survive for ~12 hours? Say my freezer is full and I need to use the refrigerator instead; is that also viable? I could put it in the back of an old refrigerator, probably.

Condensation when it comes out of the freezer is certainly something to consider. Probably the thing to do is just take it apart and blow em outta there, rather than risk water pooling behind the screen of the laptop, and on the board.