Since the dawn of humanity children have survived in sub-freezing temps just fine.
I am actually quite surprised sometimes how they stay warmer than me apparently, with a lot less insulation. Screaming metabolism and high bodyfat, all probably play a role.
I slept with my 4 mo old daughter on the floor in the living room in our house when the temp hit high teens several nights in a row and the heater had shorted out. Fireplace barely kept the living room only 40F a couple feet from it where we were. No problems with just a few blankets and comforter. Toasty warm underneath. ( House didnt get above 45 in the day either).
Would he/she possibly be uncomfortable if you were an uncaring person and unable to communicate it? maybe.
If you are a caring parent that keeps them bundled up and close to you, there would be no issues I can see either.
However, I would just plain question taking the infant. They wouldnt get anything out of it, and it would hinder your enjoyment. Id leave mine with a grandparent if possible for a trip like that.
