I've played in single digit temps for sure. Never looked at a thermometer to know exactly how cold. Also pretty sure I've played on days where the wind chill factor was in the negative numbers. I think if given the choice, I'd play in single digit temperatures rather than triple digit temperatures.
I've played in snow that was at least two feet deep on a few occasions. Makes for interesting tee shots when the pad is shoveled out and is essentially a 2-3 foot deep bunker in the snow.