Has modern fuel made manifold exhaust heating totally unnecessary (electric choke/alum.manifold), even for northern/winter driving?

6 VOLTS/POS. GRD. NW INDIANA

Heating the intake manifold went to the wayside with the advent of port fuel injection.  The heated manifolds were necessary with carburetors to keep the manifold warm to prevent the carburetor from icing up when the vehicles were driven at dew point or less ambient temperatures.

Lorena, Texas (South of Waco)

I live in a warm (sometimes too hot, like now) climate. We have very few, if any, days when the temperature drops below freezing. Lacking air conditioning on my 55 Tbird, if it's too hot or too cold for me, the car will remain in the garage. On the other hand, if your carburetor-equipped vehicle is your daily driver (unlikely for most of us), and you live in a cold climate, you probably should not block off the heat crossover.