I took my kids winter camping when they were that age. It was the most fun trips we ever had and they still will tell you to this day (they are in their 30's) that those were their favorite trips! But...I started them late winter when the weather was warm in the days. We used ensolite pads which doubled as sleds, and to this day even if I bring a thermarest in the winter, I bring a non air pad for under it in case I get a leak. I had good bags and tons of warm clothes thus the trips were very short distances. Good luck!