Depends mostly on the carb and the car. Both my old 78 Monte and the Monza before it had carbs and neither had much problem with the cold. Even with the Holley 350 2 barrel on the 262 it started and ran. Biggest issue was the oil in the saginaw getting so cold that it got stiff. Start the car and try to drop it into neutral and the lube would drag so much that it stalled the motor out. That, to me, would be cold. The Monte was more picky but that was a combination of electric choke and ground problems, not the carb itself. Don't have the care anymore but I still have that 350 and its bigger brother, a 500. Both are Holley's, both are two barrels. i even still have the flip-flopped spacer/adapter that I ginned up to mate the Holley to a Chev 2 barrel manifold. Never know when a rat rod might find its way into My Infamous Bay One.
Oh yeah, just a geographic note here, Canuckistan is actually somewhere due east of the Atlantic ocean, over by the Black Sea, if memory serves. Most of them from that neck of the dunes don't like it over here, 'cause, up here in the land of the Frozen Chosen, we mostly speak NA english, except the franglaisie in QUE, and further, again according to them, we're out and out heretics due to not having a permanent dent in our collective foreheads from pounding said body part on the ground five times a day while worshipping the sun.
So, in the true and genuine spirit of disturbing the peace whenever possible,
MERRY CHRISTMAS TO ALL,,and a hearty HO, HO, HO, Y'KNOW??
Nick